[wasm] Remove the use of private symbols for branding.

Instead, rely on the underlying instance types for WebAssembly.* types.

R=clemensh@chromium.org, rossberg@chromium.org
BUG=

Review-Url: https://codereview.chromium.org/2971093003
Cr-Commit-Position: refs/heads/master@{#46478}

src/contexts.h

@@ -366,13 +366,9 @@ enum ContextLookupFlags {
   V(NATIVE_FUNCTION_MAP_INDEX, Map, native_function_map)                       \
   V(WASM_FUNCTION_MAP_INDEX, Map, wasm_function_map)                           \
   V(WASM_INSTANCE_CONSTRUCTOR_INDEX, JSFunction, wasm_instance_constructor)    \
-  V(WASM_INSTANCE_SYM_INDEX, Symbol, wasm_instance_sym)                        \
   V(WASM_MEMORY_CONSTRUCTOR_INDEX, JSFunction, wasm_memory_constructor)        \
-  V(WASM_MEMORY_SYM_INDEX, Symbol, wasm_memory_sym)                            \
   V(WASM_MODULE_CONSTRUCTOR_INDEX, JSFunction, wasm_module_constructor)        \
-  V(WASM_MODULE_SYM_INDEX, Symbol, wasm_module_sym)                            \
   V(WASM_TABLE_CONSTRUCTOR_INDEX, JSFunction, wasm_table_constructor)          \
-  V(WASM_TABLE_SYM_INDEX, Symbol, wasm_table_sym)                              \
   V(TYPED_ARRAY_FUN_INDEX, JSFunction, typed_array_function)                   \
   V(TYPED_ARRAY_PROTOTYPE_INDEX, JSObject, typed_array_prototype)              \
   V(UINT16_ARRAY_FUN_INDEX, JSFunction, uint16_array_fun)                      \

src/wasm/module-compiler.cc

@@ -1318,7 +1318,7 @@ int InstanceBuilder::ProcessImports(Handle<FixedArray> code_table,
         break;
       }
       case kExternalTable: {
-        if (!WasmJs::IsWasmTableObject(isolate_, value)) {
+        if (!value->IsWasmTableObject()) {
           ReportLinkError("table import requires a WebAssembly.Table", index,
                           module_name, import_name);
           return -1;
@@ -1390,13 +1390,12 @@ int InstanceBuilder::ProcessImports(Handle<FixedArray> code_table,
         // Validation should have failed if more than one memory object was
         // provided.
         DCHECK(!instance->has_memory_object());
-        if (!WasmJs::IsWasmMemoryObject(isolate_, value)) {
+        if (!value->IsWasmMemoryObject()) {
           ReportLinkError("memory import must be a WebAssembly.Memory object",
                           index, module_name, import_name);
           return -1;
         }
         auto memory = Handle<WasmMemoryObject>::cast(value);
-        DCHECK(WasmJs::IsWasmMemoryObject(isolate_, memory));
         instance->set_memory_object(*memory);
         memory_ = Handle<JSArrayBuffer>(memory->array_buffer(), isolate_);
         uint32_t imported_cur_pages = static_cast<uint32_t>(

src/wasm/wasm-objects.cc

@@ -162,8 +162,6 @@ Handle<WasmModuleObject> WasmModuleObject::New(
       isolate->native_context()->wasm_module_constructor());
   auto module_object = Handle<WasmModuleObject>::cast(
       isolate->factory()->NewJSObject(module_cons));
-  Handle<Symbol> module_sym(isolate->native_context()->wasm_module_sym());
-  Object::SetProperty(module_object, module_sym, module_object, STRICT).Check();
   module_object->set_compiled_module(*compiled_module);
   Handle<WeakCell> link_to_module =
       isolate->factory()->NewWeakCell(module_object);
@@ -190,8 +188,6 @@ Handle<WasmTableObject> WasmTableObject::New(Isolate* isolate, uint32_t initial,
 
   Handle<FixedArray> dispatch_tables = isolate->factory()->NewFixedArray(0);
   table_obj->set_dispatch_tables(*dispatch_tables);
-  Handle<Symbol> table_sym(isolate->native_context()->wasm_table_sym());
-  Object::SetProperty(table_obj, table_sym, table_obj, STRICT).Check();
   return Handle<WasmTableObject>::cast(table_obj);
 }
 
@@ -327,8 +323,6 @@ Handle<WasmMemoryObject> WasmMemoryObject::New(Isolate* isolate,
   }
   memory_obj->set_array_buffer(*buffer);
   memory_obj->set_maximum_pages(maximum);
-  Handle<Symbol> memory_sym(isolate->native_context()->wasm_memory_sym());
-  Object::SetProperty(memory_obj, memory_sym, memory_obj, STRICT).Check();
   return Handle<WasmMemoryObject>::cast(memory_obj);
 }
 
@@ -436,9 +430,6 @@ Handle<WasmInstanceObject> WasmInstanceObject::New(
   Handle<JSObject> instance_object =
       isolate->factory()->NewJSObject(instance_cons, TENURED);
 
-  Handle<Symbol> instance_sym(isolate->native_context()->wasm_instance_sym());
-  Object::SetProperty(instance_object, instance_sym, instance_object, STRICT)
-      .Check();
   Handle<WasmInstanceObject> instance(
       reinterpret_cast<WasmInstanceObject*>(*instance_object), isolate);