[wasm] Call a runtime function for a MemorySize instruction.

src/wasm/wasm-module.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_WASM_MODULE_H_
 #define V8_WASM_MODULE_H_
 
 #include <memory>
 
 #include "src/api.h"
@@ skipping 516 matching lines @@
                                            ModuleOrigin origin);
 
 // Get the number of imported functions for a WASM instance.
 uint32_t GetNumImportedFunctions(Handle<JSObject> wasm_object);
 
 // Assumed to be called with a code object associated to a wasm module instance.
 // Intended to be called from runtime functions.
 // Returns nullptr on failing to get owning instance.
 Object* GetOwningWasmInstance(Code* code);
 
+int32_t GetInstanceMemorySize(Isolate* isolate, Handle<JSObject> instance);
+
 int32_t GrowInstanceMemory(Isolate* isolate, Handle<JSObject> instance,
                            uint32_t pages);
 
 namespace testing {
 
 void ValidateInstancesChain(Isolate* isolate, Handle<JSObject> module_obj,
                             int instance_count);
 void ValidateModuleState(Isolate* isolate, Handle<JSObject> module_obj);
 void ValidateOrphanedInstance(Isolate* isolate, Handle<JSObject> instance);
 
 }  // namespace testing
 }  // namespace wasm
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_WASM_MODULE_H_