[wasm] Introduce instance types for WebAssembly.* objects.

src/objects.cc

Index: src/objects.cc
diff --git a/src/objects.cc b/src/objects.cc
index 7179c8c3f77850c777d263299348f338056f1f50..0ccfb8126dadfc7da7ab5739b30dc1acd4f92a2e 100644
--- a/src/objects.cc
+++ b/src/objects.cc
@@ -1290,6 +1290,82 @@ void JSObject::EnsureWritableFastElements(Handle<JSObject> object) {
   isolate->counters()->cow_arrays_converted()->Increment();
 }
 
+int JSObject::GetHeaderSize(InstanceType type) {
+  switch (type) {
+    case JS_OBJECT_TYPE:
+    case JS_API_OBJECT_TYPE:
+    case JS_SPECIAL_API_OBJECT_TYPE:
+      return JSObject::kHeaderSize;
+    case JS_GENERATOR_OBJECT_TYPE:
+      return JSGeneratorObject::kSize;
+    case JS_ASYNC_GENERATOR_OBJECT_TYPE:
+      return JSAsyncGeneratorObject::kSize;
+    case JS_GLOBAL_PROXY_TYPE:
+      return JSGlobalProxy::kSize;
+    case JS_GLOBAL_OBJECT_TYPE:
+      return JSGlobalObject::kSize;
+    case JS_BOUND_FUNCTION_TYPE:
+      return JSBoundFunction::kSize;
+    case JS_FUNCTION_TYPE:
+      return JSFunction::kSize;
+    case JS_VALUE_TYPE:
+      return JSValue::kSize;
+    case JS_DATE_TYPE:
+      return JSDate::kSize;
+    case JS_ARRAY_TYPE:
+      return JSArray::kSize;
+    case JS_ARRAY_BUFFER_TYPE:
+      return JSArrayBuffer::kSize;
+    case JS_TYPED_ARRAY_TYPE:
+      return JSTypedArray::kSize;
+    case JS_DATA_VIEW_TYPE:
+      return JSDataView::kSize;
+    case JS_SET_TYPE:
+      return JSSet::kSize;
+    case JS_MAP_TYPE:
+      return JSMap::kSize;
+    case JS_SET_ITERATOR_TYPE:
+      return JSSetIterator::kSize;
+    case JS_MAP_ITERATOR_TYPE:
+      return JSMapIterator::kSize;
+    case JS_WEAK_MAP_TYPE:
+      return JSWeakMap::kSize;
+    case JS_WEAK_SET_TYPE:
+      return JSWeakSet::kSize;
+    case JS_PROMISE_CAPABILITY_TYPE:
+      return JSPromiseCapability::kSize;
+    case JS_PROMISE_TYPE:
+      return JSPromise::kSize;
+    case JS_REGEXP_TYPE:
+      return JSRegExp::kSize;
+    case JS_CONTEXT_EXTENSION_OBJECT_TYPE:
+      return JSObject::kHeaderSize;
+    case JS_MESSAGE_OBJECT_TYPE:
+      return JSMessageObject::kSize;
+    case JS_ARGUMENTS_TYPE:
+      return JSArgumentsObject::kHeaderSize;
+    case JS_ERROR_TYPE:
+      return JSObject::kHeaderSize;
+    case JS_STRING_ITERATOR_TYPE:
+      return JSStringIterator::kSize;
+    case JS_MODULE_NAMESPACE_TYPE:
+      return JSModuleNamespace::kHeaderSize;
+    case WASM_INSTANCE_TYPE:
+      return WasmInstanceObject::kSize;
+    case WASM_MEMORY_TYPE:
+      return WasmMemoryObject::kSize;
+    case WASM_MODULE_TYPE:
+      return WasmModuleObject::kSize;
+    case WASM_TABLE_TYPE:
+      return WasmTableObject::kSize;
+    default:
+      if (type >= FIRST_ARRAY_ITERATOR_TYPE &&
+          type <= LAST_ARRAY_ITERATOR_TYPE) {
+        return JSArrayIterator::kSize;
+      }
+      UNREACHABLE();
+  }
+}
 
 // ES6 9.5.1
 // static
@@ -3011,6 +3087,10 @@ VisitorId Map::GetVisitorId(Map* map) {
 
     case JS_PROMISE_CAPABILITY_TYPE:
     case JS_PROMISE_TYPE:
+    case WASM_INSTANCE_TYPE:
+    case WASM_MEMORY_TYPE:
+    case WASM_MODULE_TYPE:
+    case WASM_TABLE_TYPE:
     case JS_BOUND_FUNCTION_TYPE:
       return has_unboxed_fields ? kVisitJSObject : kVisitJSObjectFast;
     case JS_API_OBJECT_TYPE: