[wasm] Avoid double-serializing the wire bytes

src/d8.h

Index: src/d8.h
diff --git a/src/d8.h b/src/d8.h
index e831f8eabf69f2db5e7ea4e9e925202867eaf2f5..fad12c6b9f0b94f5f49c253043ef5bdb248ed88b 100644
--- a/src/d8.h
+++ b/src/d8.h
@@ -376,6 +376,9 @@ class Shell : public i::AllStatic {
   static void Version(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void Read(const v8::FunctionCallbackInfo<v8::Value>& args);
   static void ReadBuffer(const v8::FunctionCallbackInfo<v8::Value>& args);
+  static void ExperimentalDoubleAdder(
+      const v8::FunctionCallbackInfo<v8::Value>& args);
+  static double ExperimentalNativeDoubleAdder(double a, double b);
   static Local<String> ReadFromStdin(Isolate* isolate);
   static void ReadLine(const v8::FunctionCallbackInfo<v8::Value>& args) {
     args.GetReturnValue().Set(ReadFromStdin(args.GetIsolate()));