[wasm-gc][asm-js] Consider gc disabled for asm-js modules

An asm-js module has all wasm feature flags disabled, despite the global
flag configuration. Therefore, in WasmExportedFunction::New, we should
retrieve the enabled features from the NativeModule instead of the
flags.

Bug: chromium:1279151
Change-Id: Ic44fe535baa7cb851644457cce533c24d4c9824e
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3338256Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Manos Koukoutos <manoskouk@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78368}

src/wasm/wasm-objects.cc

@@ -1920,7 +1920,9 @@ Handle<WasmExportedFunction> WasmExportedFunction::New(
   const wasm::FunctionSig* sig = instance->module()->functions[func_index].sig;
   Address call_target = instance->GetCallTarget(func_index);
   Handle<Map> rtt;
-  if (FLAG_experimental_wasm_gc) {
+  bool has_gc =
+      instance->module_object().native_module()->enabled_features().has_gc();
+  if (has_gc) {
     int sig_index = instance->module()->functions[func_index].sig_index;
     // TODO(7748): Create funcref RTTs lazily?
     rtt = handle(Map::cast(instance->managed_object_maps().get(sig_index)),

test/mjsunit/regress/wasm/regress-1279151.js

+// Copyright 2021 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.
+
+// Flags: --experimental-wasm-gc
+
+// --experimental-wasm-gc should not affect asm-js modules.
+
+function NewModule() {
+  "use asm";
+  function foo() {}
+  return {foo:foo};
+};
+
+var v = NewModule();