deps: update v8 to 4.4.63.25

Includes cherry-picks for:
 * JitCodeEvent patch: https://crrev.com/f7969b1d5a55e66237221a463daf422ac7611788
 * argparse patch: https://crrev.com/44bc918458481d60b08d5566f0f31a79e39b85d7

deps/v8/include/v8-version.h

@@ -11,7 +11,7 @@
 #define V8_MAJOR_VERSION 4
 #define V8_MINOR_VERSION 4
 #define V8_BUILD_NUMBER 63
-#define V8_PATCH_LEVEL 12
+#define V8_PATCH_LEVEL 25
 
 // Use 1 for candidates and 0 otherwise.
 // (Boolean macro values are not supported by all preprocessors.)

deps/v8/src/api.cc

@@ -345,12 +345,14 @@ StartupData V8::CreateSnapshotDataBlob(const char* custom_source) {
     base::ElapsedTimer timer;
     timer.Start();
     Isolate::Scope isolate_scope(isolate);
+    internal_isolate->set_creating_default_snapshot(true);
     internal_isolate->Init(NULL);
     Persistent<Context> context;
     i::Snapshot::Metadata metadata;
     {
       HandleScope handle_scope(isolate);
       Handle<Context> new_context = Context::New(isolate);
+      internal_isolate->set_creating_default_snapshot(false);
       context.Reset(isolate, new_context);
       if (custom_source != NULL) {
         metadata.set_embeds_script(true);
@@ -379,7 +381,7 @@ StartupData V8::CreateSnapshotDataBlob(const char* custom_source) {
       i::SnapshotByteSink context_sink;
       i::PartialSerializer context_ser(internal_isolate, &ser, &context_sink);
       context_ser.Serialize(&raw_context);
-      ser.SerializeWeakReferences();
+      ser.SerializeWeakReferencesAndDeferred();
 
       result = i::Snapshot::CreateSnapshotBlob(ser, context_ser, metadata);
     }

deps/v8/src/arm/assembler-arm-inl.h

@@ -432,9 +432,7 @@ void Assembler::CheckBuffer() {
   if (buffer_space() <= kGap) {
     GrowBuffer();
   }
-  if (pc_offset() >= next_buffer_check_) {
-    CheckConstPool(false, true);
-  }
+  MaybeCheckConstPool();
 }
 
 

deps/v8/src/arm/assembler-arm.cc

@@ -1298,7 +1298,7 @@ void Assembler::addrmod5(Instr instr, CRegister crd, const MemOperand& x) {
 }
 
 
-int Assembler::branch_offset(Label* L, bool jump_elimination_allowed) {
+int Assembler::branch_offset(Label* L) {
   int target_pos;
   if (L->is_bound()) {
     target_pos = L->pos();
@@ -1315,7 +1315,8 @@ int Assembler::branch_offset(Label* L, bool jump_elimination_allowed) {
 
   // Block the emission of the constant pool, since the branch instruction must
   // be emitted at the pc offset recorded by the label.
-  BlockConstPoolFor(1);
+  if (!is_const_pool_blocked()) BlockConstPoolFor(1);
+
   return target_pos - (pc_offset() + kPcLoadDelta);
 }
 
@@ -1367,6 +1368,24 @@ void Assembler::bx(Register target, Condition cond) {  // v5 and above, plus v4t
 }
 
 
+void Assembler::b(Label* L, Condition cond) {
+  CheckBuffer();
+  b(branch_offset(L), cond);
+}
+
+
+void Assembler::bl(Label* L, Condition cond) {
+  CheckBuffer();
+  bl(branch_offset(L), cond);
+}
+
+
+void Assembler::blx(Label* L) {
+  CheckBuffer();
+  blx(branch_offset(L));
+}
+
+
 // Data-processing instructions.
 
 void Assembler::and_(Register dst, Register src1, const Operand& src2,

deps/v8/src/arm/assembler-arm.h

@@ -746,7 +746,7 @@ class Assembler : public AssemblerBase {
   // Returns the branch offset to the given label from the current code position
   // Links the label to the current position if it is still unbound
   // Manages the jump elimination optimization if the second parameter is true.
-  int branch_offset(Label* L, bool jump_elimination_allowed);
+  int branch_offset(Label* L);
 
   // Returns true if the given pc address is the start of a constant pool load
   // instruction sequence.
@@ -852,13 +852,11 @@ class Assembler : public AssemblerBase {
   void bx(Register target, Condition cond = al);  // v5 and above, plus v4t
 
   // Convenience branch instructions using labels
-  void b(Label* L, Condition cond = al)  {
-    b(branch_offset(L, cond == al), cond);
-  }
-  void b(Condition cond, Label* L)  { b(branch_offset(L, cond == al), cond); }
-  void bl(Label* L, Condition cond = al)  { bl(branch_offset(L, false), cond); }
-  void bl(Condition cond, Label* L)  { bl(branch_offset(L, false), cond); }
-  void blx(Label* L)  { blx(branch_offset(L, false)); }  // v5 and above
+  void b(Label* L, Condition cond = al);
+  void b(Condition cond, Label* L) { b(L, cond); }
+  void bl(Label* L, Condition cond = al);
+  void bl(Condition cond, Label* L) { bl(L, cond); }
+  void blx(Label* L);  // v5 and above
 
   // Data-processing instructions
 
@@ -1536,6 +1534,12 @@ class Assembler : public AssemblerBase {
   // Check if is time to emit a constant pool.
   void CheckConstPool(bool force_emit, bool require_jump);
 
+  void MaybeCheckConstPool() {
+    if (pc_offset() >= next_buffer_check_) {
+      CheckConstPool(false, true);
+    }
+  }
+
   // Allocate a constant pool of the correct size for the generated code.
   Handle<ConstantPoolArray> NewConstantPool(Isolate* isolate);
 

deps/v8/src/arm64/code-stubs-arm64.cc

@@ -2286,27 +2286,16 @@ void RegExpExecStub::Generate(MacroAssembler* masm) {
   Register last_match_info_elements = x21;
   Register code_object = x22;
 
-  // TODO(jbramley): Is it necessary to preserve these? I don't think ARM does.
-  CPURegList used_callee_saved_registers(subject,
-                                         regexp_data,
-                                         last_match_info_elements,
-                                         code_object);
-  __ PushCPURegList(used_callee_saved_registers);
-
   // Stack frame.
-  //  jssp[0] : x19
-  //  jssp[8] : x20
-  //  jssp[16]: x21
-  //  jssp[24]: x22
-  //  jssp[32]: last_match_info (JSArray)
-  //  jssp[40]: previous index
-  //  jssp[48]: subject string
-  //  jssp[56]: JSRegExp object
-
-  const int kLastMatchInfoOffset = 4 * kPointerSize;
-  const int kPreviousIndexOffset = 5 * kPointerSize;
-  const int kSubjectOffset = 6 * kPointerSize;
-  const int kJSRegExpOffset = 7 * kPointerSize;
+  //  jssp[00]: last_match_info (JSArray)
+  //  jssp[08]: previous index
+  //  jssp[16]: subject string
+  //  jssp[24]: JSRegExp object
+
+  const int kLastMatchInfoOffset = 0 * kPointerSize;
+  const int kPreviousIndexOffset = 1 * kPointerSize;
+  const int kSubjectOffset = 2 * kPointerSize;
+  const int kJSRegExpOffset = 3 * kPointerSize;
 
   // Ensure that a RegExp stack is allocated.
   ExternalReference address_of_regexp_stack_memory_address =
@@ -2673,7 +2662,6 @@ void RegExpExecStub::Generate(MacroAssembler* masm) {
 
   // Return last match info.
   __ Peek(x0, kLastMatchInfoOffset);
-  __ PopCPURegList(used_callee_saved_registers);
   // Drop the 4 arguments of the stub from the stack.
   __ Drop(4);
   __ Ret();
@@ -2696,13 +2684,11 @@ void RegExpExecStub::Generate(MacroAssembler* masm) {
 
   __ Bind(&failure);
   __ Mov(x0, Operand(isolate()->factory()->null_value()));
-  __ PopCPURegList(used_callee_saved_registers);
   // Drop the 4 arguments of the stub from the stack.
   __ Drop(4);
   __ Ret();
 
   __ Bind(&runtime);
-  __ PopCPURegList(used_callee_saved_registers);
   __ TailCallRuntime(Runtime::kRegExpExec, 4, 1);
 
   // Deferred code for string handling.

deps/v8/src/bootstrapper.cc

@@ -2813,6 +2813,7 @@ void Genesis::TransferNamedProperties(Handle<JSObject> from,
         if (value->IsPropertyCell()) {
           value = handle(PropertyCell::cast(*value)->value(), isolate());
         }
+        if (value->IsTheHole()) continue;
         PropertyDetails details = properties->DetailsAt(i);
         DCHECK_EQ(kData, details.kind());
         JSObject::AddProperty(to, key, value, details.attributes());

deps/v8/src/compiler/arm/code-generator-arm.cc

@@ -316,6 +316,8 @@ void CodeGenerator::AssembleDeconstructActivationRecord() {
 void CodeGenerator::AssembleArchInstruction(Instruction* instr) {
   ArmOperandConverter i(this, instr);
 
+  masm()->MaybeCheckConstPool();
+
   switch (ArchOpcodeField::decode(instr->opcode())) {
     case kArchCallCodeObject: {
       EnsureSpaceForLazyDeopt();

deps/v8/src/flag-definitions.h

@@ -199,7 +199,7 @@ DEFINE_IMPLICATION(es_staging, harmony)
 #define HARMONY_STAGED(V)                               \
   V(harmony_rest_parameters, "harmony rest parameters") \
   V(harmony_spreadcalls, "harmony spread-calls")        \
-  V(harmony_tostring, "harmony toString")               \
+  V(harmony_tostring, "harmony toString")
 
 // Features that are shipping (turned on by default, but internal flag remains).
 #define HARMONY_SHIPPING(V)                                                \

deps/v8/src/ic/ic.cc

@@ -1112,7 +1112,39 @@ void LoadIC::UpdateCaches(LookupIterator* lookup) {
       code = slow_stub();
     }
   } else {
-    code = ComputeHandler(lookup);
+    if (lookup->state() == LookupIterator::ACCESSOR) {
+      Handle<Object> accessors = lookup->GetAccessors();
+      Handle<Map> map = receiver_map();
+      if (accessors->IsExecutableAccessorInfo()) {
+        Handle<ExecutableAccessorInfo> info =
+            Handle<ExecutableAccessorInfo>::cast(accessors);
+        if ((v8::ToCData<Address>(info->getter()) != 0) &&
+            !ExecutableAccessorInfo::IsCompatibleReceiverMap(isolate(), info,
+                                                             map)) {
+          TRACE_GENERIC_IC(isolate(), "LoadIC", "incompatible receiver type");
+          code = slow_stub();
+        }
+      } else if (accessors->IsAccessorPair()) {
+        Handle<Object> getter(Handle<AccessorPair>::cast(accessors)->getter(),
+                              isolate());
+        Handle<JSObject> holder = lookup->GetHolder<JSObject>();
+        Handle<Object> receiver = lookup->GetReceiver();
+        if (getter->IsJSFunction() && holder->HasFastProperties()) {
+          Handle<JSFunction> function = Handle<JSFunction>::cast(getter);
+          if (receiver->IsJSObject() || function->IsBuiltin() ||
+              !is_sloppy(function->shared()->language_mode())) {
+            CallOptimization call_optimization(function);
+            if (call_optimization.is_simple_api_call() &&
+                !call_optimization.IsCompatibleReceiver(receiver, holder)) {
+              TRACE_GENERIC_IC(isolate(), "LoadIC",
+                               "incompatible receiver type");
+              code = slow_stub();
+            }
+          }
+        }
+      }
+    }
+    if (code.is_null()) code = ComputeHandler(lookup);
   }
 
   PatchCache(lookup->name(), code);
@@ -1242,6 +1274,8 @@ Handle<Code> LoadIC::CompileHandler(LookupIterator* lookup,
         if (v8::ToCData<Address>(info->getter()) == 0) break;
         if (!ExecutableAccessorInfo::IsCompatibleReceiverMap(isolate(), info,
                                                              map)) {
+          // This case should be already handled in LoadIC::UpdateCaches.
+          UNREACHABLE();
           break;
         }
         if (!holder->HasFastProperties()) break;
@@ -1262,10 +1296,14 @@ Handle<Code> LoadIC::CompileHandler(LookupIterator* lookup,
         }
         CallOptimization call_optimization(function);
         NamedLoadHandlerCompiler compiler(isolate(), map, holder, cache_holder);
-        if (call_optimization.is_simple_api_call() &&
-            call_optimization.IsCompatibleReceiver(receiver, holder)) {
-          return compiler.CompileLoadCallback(lookup->name(), call_optimization,
-                                              lookup->GetAccessorIndex());
+        if (call_optimization.is_simple_api_call()) {
+          if (call_optimization.IsCompatibleReceiver(receiver, holder)) {
+            return compiler.CompileLoadCallback(
+                lookup->name(), call_optimization, lookup->GetAccessorIndex());
+          } else {
+            // This case should be already handled in LoadIC::UpdateCaches.
+            UNREACHABLE();
+          }
         }
         int expected_arguments =
             function->shared()->internal_formal_parameter_count();

deps/v8/src/isolate.h

@@ -389,6 +389,7 @@ typedef List<HeapObject*> DebugObjectCache;
   V(uint32_t, per_isolate_assert_data, 0xFFFFFFFFu)                            \
   V(PromiseRejectCallback, promise_reject_callback, NULL)                      \
   V(const v8::StartupData*, snapshot_blob, NULL)                               \
+  V(bool, creating_default_snapshot, false)                                    \
   ISOLATE_INIT_SIMULATOR_LIST(V)
 
 #define THREAD_LOCAL_TOP_ACCESSOR(type, name)                        \

deps/v8/src/mips/assembler-mips-inl.h

@@ -500,8 +500,8 @@ void Assembler::CheckBuffer() {
 }
 
 
-void Assembler::CheckTrampolinePoolQuick() {
-  if (pc_offset() >= next_buffer_check_) {
+void Assembler::CheckTrampolinePoolQuick(int extra_instructions) {
+  if (pc_offset() >= next_buffer_check_ - extra_instructions * kInstrSize) {
     CheckTrampolinePool();
   }
 }

deps/v8/src/mips/assembler-mips.cc

@@ -795,7 +795,7 @@ void Assembler::bind_to(Label* L, int pos) {
           trampoline_pos = get_trampoline_entry(fixup_pos);
           CHECK(trampoline_pos != kInvalidSlotPos);
         }
-        DCHECK((trampoline_pos - fixup_pos) <= kMaxBranchOffset);
+        CHECK((trampoline_pos - fixup_pos) <= kMaxBranchOffset);
         target_at_put(fixup_pos, trampoline_pos, false);
         fixup_pos = trampoline_pos;
         dist = pos - fixup_pos;
@@ -1415,6 +1415,7 @@ void Assembler::jal(int32_t target) {
 
 
 void Assembler::jalr(Register rs, Register rd) {
+  DCHECK(rs.code() != rd.code());
   BlockTrampolinePoolScope block_trampoline_pool(this);
   positions_recorder()->WriteRecordedPositions();
   GenInstrRegister(SPECIAL, rs, zero_reg, rd, 0, JALR);
@@ -2633,6 +2634,7 @@ void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data) {
 
 
 void Assembler::BlockTrampolinePoolFor(int instructions) {
+  CheckTrampolinePoolQuick(instructions);
   BlockTrampolinePoolBefore(pc_offset() + instructions * kInstrSize);
 }
 

deps/v8/src/mips/assembler-mips.h

@@ -1253,7 +1253,7 @@ class Assembler : public AssemblerBase {
   inline void CheckBuffer();
   void GrowBuffer();
   inline void emit(Instr x);
-  inline void CheckTrampolinePoolQuick();
+  inline void CheckTrampolinePoolQuick(int extra_instructions = 0);
 
   // Instruction generation.
   // We have 3 different kind of encoding layout on MIPS.

deps/v8/src/mips/code-stubs-mips.cc

@@ -4028,8 +4028,8 @@ void DirectCEntryStub::GenerateCall(MacroAssembler* masm,
   intptr_t loc =
       reinterpret_cast<intptr_t>(GetCode().location());
   __ Move(t9, target);
-  __ li(ra, Operand(loc, RelocInfo::CODE_TARGET), CONSTANT_SIZE);
-  __ Call(ra);
+  __ li(at, Operand(loc, RelocInfo::CODE_TARGET), CONSTANT_SIZE);
+  __ Call(at);
 }
 
 

deps/v8/src/mips64/assembler-mips64-inl.h

@@ -504,8 +504,8 @@ void Assembler::CheckBuffer() {
 }
 
 
-void Assembler::CheckTrampolinePoolQuick() {
-  if (pc_offset() >= next_buffer_check_) {
+void Assembler::CheckTrampolinePoolQuick(int extra_instructions) {
+  if (pc_offset() >= next_buffer_check_ - extra_instructions * kInstrSize) {
     CheckTrampolinePool();
   }
 }

deps/v8/src/mips64/assembler-mips64.cc

@@ -780,7 +780,7 @@ void Assembler::bind_to(Label* L, int pos) {
           trampoline_pos = get_trampoline_entry(fixup_pos);
           CHECK(trampoline_pos != kInvalidSlotPos);
         }
-        DCHECK((trampoline_pos - fixup_pos) <= kMaxBranchOffset);
+        CHECK((trampoline_pos - fixup_pos) <= kMaxBranchOffset);
         target_at_put(fixup_pos, trampoline_pos, false);
         fixup_pos = trampoline_pos;
         dist = pos - fixup_pos;
@@ -1396,6 +1396,7 @@ void Assembler::jal(int64_t target) {
 
 
 void Assembler::jalr(Register rs, Register rd) {
+  DCHECK(rs.code() != rd.code());
   BlockTrampolinePoolScope block_trampoline_pool(this);
   positions_recorder()->WriteRecordedPositions();
   GenInstrRegister(SPECIAL, rs, zero_reg, rd, 0, JALR);
@@ -2809,6 +2810,7 @@ void Assembler::RecordRelocInfo(RelocInfo::Mode rmode, intptr_t data) {
 
 
 void Assembler::BlockTrampolinePoolFor(int instructions) {
+  CheckTrampolinePoolQuick(instructions);
   BlockTrampolinePoolBefore(pc_offset() + instructions * kInstrSize);
 }
 

deps/v8/src/mips64/assembler-mips64.h

@@ -1288,7 +1288,7 @@ class Assembler : public AssemblerBase {
   void GrowBuffer();
   inline void emit(Instr x);
   inline void emit(uint64_t x);
-  inline void CheckTrampolinePoolQuick();
+  inline void CheckTrampolinePoolQuick(int extra_instructions = 0);
 
   // Instruction generation.
   // We have 3 different kind of encoding layout on MIPS.