[EH] Add metadce test and LTO test for Wasm EH (#16924)

Author: aheejin

tests/other/metadce/test_metadce_cxx_except_wasm.exports

@@ -0,0 +1,15 @@
+__errno_location
+__indirect_function_table
+__wasm_call_ctors
+dynCall_iiiiiijj
+dynCall_iiiiij
+dynCall_iiiiijj
+dynCall_jiji
+dynCall_viijii
+free
+main
+memory
+setThrew
+stackAlloc
+stackRestore
+stackSave

tests/other/metadce/test_metadce_cxx_except_wasm.imports

@@ -0,0 +1,11 @@
+env.abort
+env.emscripten_memcpy_big
+env.emscripten_resize_heap
+env.setTempRet0
+env.strftime_l
+wasi_snapshot_preview1.environ_get
+wasi_snapshot_preview1.environ_sizes_get
+wasi_snapshot_preview1.fd_close
+wasi_snapshot_preview1.fd_read
+wasi_snapshot_preview1.fd_seek
+wasi_snapshot_preview1.fd_write

tests/other/metadce/test_metadce_cxx_except_wasm.jssize

@@ -0,0 +1 @@
+26538

tests/other/metadce/test_metadce_cxx_except_wasm.sent

@@ -0,0 +1,11 @@
+abort
+emscripten_memcpy_big
+emscripten_resize_heap
+environ_get
+environ_sizes_get
+fd_close
+fd_read
+fd_seek
+fd_write
+setTempRet0
+strftime_l

tests/other/metadce/test_metadce_cxx_except_wasm.size

@@ -0,0 +1 @@
+135339

tests/test_other.py

@@ -7341,6 +7341,8 @@ def test_metadce_minimal_pthreads(self):
     # exceptions does not pull in demangling by default, which increases code size
     'mangle':   (['-O2', '-fexceptions',
                   '-sDEMANGLE_SUPPORT'], [], ['waka']), # noqa
+    # Wasm EH's code size increase is smaller than that of Emscripten EH
+    'except_wasm':   (['-O2', '-fwasm-exceptions'], [], ['waka']), # noqa
     # eval_ctors 1 can partially optimize, but runs into getenv() for locale
     # code. mode 2 ignores those and fully optimizes out the ctors
     'ctors1':    (['-O2', '-sEVAL_CTORS'],   [], ['waka']), # noqa
@@ -7651,7 +7653,8 @@ def test_lto(self):
 
   @parameterized({
     'noexcept': [],
-    'except': ['-sDISABLE_EXCEPTION_CATCHING=0']
+    'except': ['-sDISABLE_EXCEPTION_CATCHING=0'],
+    'except_wasm': ['-fwasm-exceptions']
   })
   def test_lto_libcxx(self, *args):
     self.run_process([EMXX, test_file('hello_libcxx.cpp'), '-flto'] + list(args))