[Hexagon] Set the default compilation target to V68 (#125239)

Set the default compilation target to V68 if no Hexagon processor is
specified at the command-line.
Add the elf header changes for v81/v83/v85 architectures.

Author: iajbar

clang/lib/Driver/ToolChains/Hexagon.cpp

@@ -802,9 +802,7 @@ bool HexagonToolChain::isAutoHVXEnabled(const llvm::opt::ArgList &Args) {
 // Returns the default CPU for Hexagon. This is the default compilation target
 // if no Hexagon processor is selected at the command-line.
 //
-StringRef HexagonToolChain::GetDefaultCPU() {
-  return "hexagonv60";
-}
+StringRef HexagonToolChain::GetDefaultCPU() { return "hexagonv68"; }
 
 StringRef HexagonToolChain::GetTargetCPUVersion(const ArgList &Args) {
   Arg *CpuArg = nullptr;

clang/test/Driver/hexagon-cpu-default.c

@@ -0,0 +1,4 @@
+// CHECK: "-target-cpu" "hexagonv68"
+
+// RUN: %clang -c %s -### --target=hexagon-unknown-elf \
+// RUN:  2>&1 | FileCheck  %s

llvm/include/llvm/BinaryFormat/ELF.h

@@ -619,6 +619,7 @@ enum {
   EF_HEXAGON_MACH_V5 = 0x00000004,   // Hexagon V5
   EF_HEXAGON_MACH_V55 = 0x00000005,  // Hexagon V55
   EF_HEXAGON_MACH_V60 = 0x00000060,  // Hexagon V60
+  EF_HEXAGON_MACH_V61 = 0x00000061,  // Hexagon V61
   EF_HEXAGON_MACH_V62 = 0x00000062,  // Hexagon V62
   EF_HEXAGON_MACH_V65 = 0x00000065,  // Hexagon V65
   EF_HEXAGON_MACH_V66 = 0x00000066,  // Hexagon V66
@@ -630,7 +631,11 @@ enum {
   EF_HEXAGON_MACH_V71T = 0x00008071, // Hexagon V71T
   EF_HEXAGON_MACH_V73 = 0x00000073,  // Hexagon V73
   EF_HEXAGON_MACH_V75 = 0x00000075,  // Hexagon V75
+  EF_HEXAGON_MACH_V77 = 0x00000077,  // Hexagon V77
   EF_HEXAGON_MACH_V79 = 0x00000079,  // Hexagon V79
+  EF_HEXAGON_MACH_V81 = 0x00000081,  // Hexagon V81
+  EF_HEXAGON_MACH_V83 = 0x00000083,  // Hexagon V83
+  EF_HEXAGON_MACH_V85 = 0x00000085,  // Hexagon V85
   EF_HEXAGON_MACH = 0x000003ff,      // Hexagon V..
 
   // Highest ISA version flags
@@ -642,6 +647,7 @@ enum {
   EF_HEXAGON_ISA_V5 = 0x00000040,   // Hexagon V5 ISA
   EF_HEXAGON_ISA_V55 = 0x00000050,  // Hexagon V55 ISA
   EF_HEXAGON_ISA_V60 = 0x00000060,  // Hexagon V60 ISA
+  EF_HEXAGON_ISA_V61 = 0x00000061,  // Hexagon V61 ISA
   EF_HEXAGON_ISA_V62 = 0x00000062,  // Hexagon V62 ISA
   EF_HEXAGON_ISA_V65 = 0x00000065,  // Hexagon V65 ISA
   EF_HEXAGON_ISA_V66 = 0x00000066,  // Hexagon V66 ISA
@@ -651,7 +657,11 @@ enum {
   EF_HEXAGON_ISA_V71 = 0x00000071,  // Hexagon V71 ISA
   EF_HEXAGON_ISA_V73 = 0x00000073,  // Hexagon V73 ISA
   EF_HEXAGON_ISA_V75 = 0x00000075,  // Hexagon V75 ISA
+  EF_HEXAGON_ISA_V77 = 0x00000077,  // Hexagon V77 ISA
   EF_HEXAGON_ISA_V79 = 0x00000079,  // Hexagon V79 ISA
+  EF_HEXAGON_ISA_V81 = 0x00000081,  // Hexagon V81 ISA
+  EF_HEXAGON_ISA_V83 = 0x00000083,  // Hexagon V83 ISA
+  EF_HEXAGON_ISA_V85 = 0x00000085,  // Hexagon V85 ISA
   EF_HEXAGON_ISA = 0x000003ff,      // Hexagon V.. ISA
 };