[WASM] Implements catch for the wasm low level exception mechanism.

src/isolate-inl.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_ISOLATE_INL_H_
 #define V8_ISOLATE_INL_H_
 
 #include "src/isolate.h"
 #include "src/objects-inl.h"
 
@@ skipping 58 matching lines @@
 void Isolate::clear_scheduled_exception() {
   DCHECK(!thread_local_top_.scheduled_exception_->IsException(this));
   thread_local_top_.scheduled_exception_ = heap_.the_hole_value();
 }
 
 
 bool Isolate::is_catchable_by_javascript(Object* exception) {
   return exception != heap()->termination_exception();
 }
 
+bool Isolate::is_catchable_by_wasm(Object* exception) {
+  return is_catchable_by_javascript(exception) &&
+         (exception->IsNumber() || exception->IsSmi());
+}
+
 void Isolate::FireBeforeCallEnteredCallback() {
   for (int i = 0; i < before_call_entered_callbacks_.length(); i++) {
     before_call_entered_callbacks_.at(i)(reinterpret_cast<v8::Isolate*>(this));
   }
 }
 
 Handle<JSGlobalObject> Isolate::global_object() {
   return handle(context()->global_object(), this);
 }
 
@@ skipping 46 matching lines @@
 
 bool Isolate::IsStringLengthOverflowIntact() {
   PropertyCell* has_instance_cell = heap()->string_length_protector();
   return has_instance_cell->value() == Smi::FromInt(kArrayProtectorValid);
 }
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_ISOLATE_INL_H_