[wasm] reuse the first compiled module

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 396 matching lines @@
                                                   const byte* end,
                                                   ErrorThrower* thrower,
                                                   ModuleOrigin origin);
 
 // Assumed to be called with a code object associated to a wasm module instance.
 // Intended to be called from runtime functions.
 // Returns undefined if the runtime support was not setup, nullptr if the
 // instance
 // was collected, or the instance object owning the Code object
 Object* GetOwningWasmInstance(Object* undefined, Code* code);
+
+MaybeHandle<JSArrayBuffer> GetInstanceMemory(Isolate* isolate,
+                                             Handle<JSObject> instance);
+void SetInstanceMemory(Handle<JSObject> instance, JSArrayBuffer* buffer);
+
+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_