[EH/SjLj] Support Wasm EH + Wasm SjLj (#16072)

Now that
llvm/llvm-project@eb675e9
has landed, we can use Wasm EH and Wasm SjLj together.

This PR
- enables Wasm EH + Wasm SjLj combination which was previously banned
- unifies `@with_both_exception_handling` and `@with_both_sjlj_handling`
  into `@with_both_eh_sjlj`. Given that we don't really have a
  plan to test Wasm EH + Emscripten SjLj combination going forward,
  which was meant to be only a temporary measure during the period we
  have only Wasm EH but not Wasm SjLj, I don't think it's worth the
  hassle of keeping three different decorators like
  `@with_both_exception_handling`, `@with_both_sjlj_handling`,
  `@with_both_eh_sjlj`.
- adds `@with_both_eh_sjlj` to several more tests that mix EH + SjLj
- adds one more test that mixes EH + SjLj
- duplicates `test_longjmp` into `test_longjmp_stadnalone`. I couldn't
  find a way to attach two decorators (`@with_both_eh_sjlj and
  `@also_with_standalone_wasm`) to a single test.
- adds `test_longjmp_with_and_without_exceptions` and
`test_exceptions_with_and_without_longjmp`.

Fixes #15404.

Author: aheejin

system/include/emscripten/bind.h

@@ -1884,10 +1884,9 @@ void constant(const char* name, const ConstantType& v) {
         static_cast<double>(asGenericValue(BT::toWireType(v))));
 }
 
-} // end namespace emscripten
+// EMSCRIPTEN_BINDINGS simple creates a static constructor function which
+// will get included in the program if the translation unit in which it is
+// define gets linked into the program.
+#define EMSCRIPTEN_BINDINGS(name) __attribute__((constructor)) static void __embind_init_##name(void)
 
-#define EMSCRIPTEN_BINDINGS(name)                                       \
-    static struct EmscriptenBindingInitializer_##name {                 \
-        EmscriptenBindingInitializer_##name();                          \
-    } EmscriptenBindingInitializer_##name##_instance;                   \
-    EmscriptenBindingInitializer_##name::EmscriptenBindingInitializer_##name()
+} // end namespace emscripten

system/lib/embind/bind.cpp

@@ -100,7 +100,12 @@ template <typename T> static void register_memory_view(const char* name) {
 } // namespace
 
 extern "C" {
-void EMSCRIPTEN_KEEPALIVE __embind_register_native_and_builtin_types() {
+
+// Normal initialization, executed through a global constructor. This
+// happens on the main thread; pthreads will call it manually, so make
+// sure we also export it (via EMSCRIPTEN_KEEPALIVE).
+EMSCRIPTEN_KEEPALIVE __attribute__((constructor))
+void __embind_register_native_and_builtin_types() {
   using namespace emscripten::internal;
 
   _embind_register_void(TypeID<void>::get(), "void");
@@ -161,10 +166,5 @@ void EMSCRIPTEN_KEEPALIVE __embind_register_native_and_builtin_types() {
   register_memory_view<long double>("emscripten::memory_view<long double>");
 #endif
 }
-}
 
-EMSCRIPTEN_BINDINGS(native_and_builtin_types) {
-  // Normal initialization, executed through a global constructor. This
-  // happens on the main thread; pthreads will call it manually.
-  __embind_register_native_and_builtin_types();
-}
+} // extern "C"