[wasm] Use more precise types for some WASM objects.

src/wasm/wasm-objects.cc

 // 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.
 
 #include "src/wasm/wasm-objects.h"
 #include "src/wasm/wasm-module.h"
 
 #define TRACE(...)                                      \
   do {                                                  \
     if (FLAG_trace_wasm_instances) PrintF(__VA_ARGS__); \
@@ skipping 79 matching lines @@
   compiled_module->set_weak_wasm_module(link_to_module);
   return Handle<WasmModuleObject>::cast(module_object);
 }
 
 WasmModuleObject* WasmModuleObject::cast(Object* object) {
   DCHECK(object->IsJSObject());
   // TODO(titzer): brand check for WasmModuleObject.
   return reinterpret_cast<WasmModuleObject*>(object);
 }
 
+bool WasmModuleObject::IsWasmModuleObject(Object* object) {
+  return object->IsJSObject() &&
+         JSObject::cast(object)->GetInternalFieldCount() == kFieldCount;
+}
+
+DEFINE_GETTER(WasmModuleObject, compiled_module, kCompiledModule,
+              WasmCompiledModule)
+
 Handle<WasmTableObject> WasmTableObject::New(Isolate* isolate, uint32_t initial,
                                              uint32_t maximum,
                                              Handle<FixedArray>* js_functions) {
   Handle<JSFunction> table_ctor(
       isolate->native_context()->wasm_table_constructor());
   Handle<JSObject> table_obj = isolate->factory()->NewJSObject(table_ctor);
   *js_functions = isolate->factory()->NewFixedArray(initial);
   Object* null = isolate->heap()->null_value();
   for (int i = 0; i < static_cast<int>(initial); ++i) {
     (*js_functions)->set(i, null);
@@ skipping 240 matching lines @@
 #endif
 }
 
 uint32_t WasmCompiledModule::mem_size() const {
   return has_memory() ? memory()->byte_length()->Number() : default_mem_size();
 }
 
 uint32_t WasmCompiledModule::default_mem_size() const {
   return min_mem_pages() * WasmModule::kPageSize;
 }