[wasm-gc] Use experimental wasm GC flag for string <-> array conversions

This CL decouples the Wasm GC JS interop from the experimental
string <-> array conversions as the interop is now enabled by
default, still there are some issues discovered with the
conversions.
The functions are fixed via https://chromium-review.googlesource.com/c/v8/v8/+/3916633.

Bug: chromium:1366881
Change-Id: I27730523a51d24a7ea18199e1668e8c76f0bcb4d
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3916088Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Commit-Queue: Matthias Liedtke <mliedtke@chromium.org>
Cr-Commit-Position: refs/heads/main@{#83435}

src/wasm/wasm-js.cc

@@ -17,6 +17,7 @@
 #include "src/execution/execution.h"
 #include "src/execution/isolate.h"
 #include "src/execution/messages.h"
+#include "src/flags/flags.h"
 #include "src/handles/handles.h"
 #include "src/heap/factory.h"
 #include "src/objects/fixed-array.h"
@@ -2989,9 +2990,10 @@ void WasmJs::Install(Isolate* isolate, bool exposed_on_global_object) {
   InstallFunc(isolate, webassembly, "validate", WebAssemblyValidate, 1);
   InstallFunc(isolate, webassembly, "instantiate", WebAssemblyInstantiate, 1);
 
-  // TODO(tebbi): Put this behind its own flag once --wasm-gc-js-interop gets
-  // closer to shipping.
-  if (v8_flags.wasm_gc_js_interop) {
+  // TODO(7748): These built-ins should not be shipped with wasm GC.
+  // Either a new flag will be needed or the built-ins have to be deleted prior
+  // to shipping.
+  if (v8_flags.experimental_wasm_gc) {
     SimpleInstallFunction(
         isolate, webassembly, "experimentalConvertArrayToString",
         Builtin::kExperimentalWasmConvertArrayToString, 0, true);

test/mjsunit/wasm/gc-experimental-string-conversions.js

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// Flags: --experimental-wasm-gc --wasm-gc-js-interop
+// Flags: --experimental-wasm-gc --allow-natives-syntax
 
 d8.file.execute('test/mjsunit/wasm/wasm-module-builder.js');
 
@@ -45,3 +45,24 @@ const array =
 for (let i = 0; i < string.length; ++i) {
   assertEquals(getChar(array, i), string.charCodeAt(i));
 }
+
+// Test calling built-ins with different amount of (invalid) arguments.
+function arrayToString() {
+  WebAssembly.experimentalConvertArrayToString(...arguments);
+}
+function stringToArray() {
+  WebAssembly.experimentalConvertStringToArray(...arguments);
+}
+
+let args = [];
+for (let i = 1; i <= 5; ++i) {
+  assertThrows(() => arrayToString(...args));
+  assertThrows(() => stringToArray(...args));
+  %PrepareFunctionForOptimization(arrayToString);
+  %PrepareFunctionForOptimization(stringToArray);
+  %OptimizeFunctionOnNextCall(arrayToString);
+  %OptimizeFunctionOnNextCall(stringToArray);
+  assertThrows(() => arrayToString(...args));
+  assertThrows(() => stringToArray(...args));
+  args.push(i);
+}