Reland: [v8] Stop using deprecated fields of v8::FastApiCallbackOptio…

…ns (#196)

* Reland: [v8] Stop using deprecated fields of v8::FastApiCallbackOptions

Two fields on the v8::FastApiCallbackOptions struct were deprecated
recently, fallback and wasm_memory. This PR removes uses of these two
fields in node.js.

This change is a refactoring and does not add new features. Therefore
existing tests should be sufficient.

* return correct type

src/node_wasi.cc

@@ -258,12 +258,12 @@ R WASI::WasiFunction<FT, F, R, Args...>::FastCallback(
     THROW_ERR_WASI_NOT_STARTED(isolate);
     return EinvalError<R>();
   }
-  uint8_t* memory = nullptr;
-  CHECK(LIKELY(options.wasm_memory->getStorageIfAligned(&memory)));
+  Local<ArrayBuffer> ab = wasi->memory_.Get(isolate)->Buffer();
+  size_t mem_size = ab->ByteLength();
+  char* mem_data = static_cast<char*>(ab->Data());
+  CHECK_NOT_NULL(mem_data);
 
-  return F(*wasi,
-           {reinterpret_cast<char*>(memory), options.wasm_memory->length()},
-           args...);
+  return F(*wasi, {mem_data, mem_size}, args...);
 }
 
 namespace {