Revert "Extend IsExtensible proxy trap fast path for Reflect.isExtensible"

This reverts commit 566233ae.

Reason for revert: Breaks the build

Original change's description:
> Extend IsExtensible proxy trap fast path for Reflect.isExtensible
> 
> The fast path for IsExtensible proxy trap is already implemented, we just need to use this for ReflectIsExtensible.
> Now, ReflectIsExtensible is now a Torque builtin (previously CPP). Other cases will fall back to runtime.
> 
> Bug: v8:6664
> Change-Id: Ib1c3f78d1f1a44c6628d351fed3bcdc91ca08cb5
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1645438
> Reviewed-by: Maya Lekova <mslekova@chromium.org>
> Reviewed-by: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Tamer Tas <tmrts@chromium.org>
> Commit-Queue: Z Nguyen-Huu <duongn@microsoft.com>
> Cr-Commit-Position: refs/heads/master@{#62031}

TBR=jgruber@chromium.org,mslekova@chromium.org,tmrts@chromium.org,duongn@microsoft.com

Change-Id: I92f83d8c9cbdca1a33ddd0e875551deb62d7de89
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: v8:6664
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1648241Reviewed-by: Dan Elphick <delphick@chromium.org>
Commit-Queue: Dan Elphick <delphick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62033}

BUILD.gn

@@ -961,7 +961,6 @@ torque_files = [
   "src/builtins/proxy-revoke.tq",
   "src/builtins/proxy-set-property.tq",
   "src/builtins/proxy.tq",
-  "src/builtins/reflect.tq",
   "src/builtins/regexp-replace.tq",
   "src/builtins/regexp.tq",
   "src/builtins/string.tq",

src/builtins/builtins-definitions.h

@@ -827,6 +827,7 @@ namespace internal {
   CPP(ReflectGetOwnPropertyDescriptor)                                         \
   CPP(ReflectGetPrototypeOf)                                                   \
   TFJ(ReflectHas, 2, kReceiver, kTarget, kKey)                                 \
+  CPP(ReflectIsExtensible)                                                     \
   CPP(ReflectOwnKeys)                                                          \
   CPP(ReflectPreventExtensions)                                                \
   CPP(ReflectSet)                                                              \

src/builtins/builtins-reflect.cc

@@ -136,6 +136,25 @@ BUILTIN(ReflectGetPrototypeOf) {
                            JSReceiver::GetPrototype(isolate, receiver));
 }
 
+// ES6 section 26.1.10 Reflect.isExtensible
+BUILTIN(ReflectIsExtensible) {
+  HandleScope scope(isolate);
+  DCHECK_EQ(2, args.length());
+  Handle<Object> target = args.at(1);
+
+  if (!target->IsJSReceiver()) {
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate, NewTypeError(MessageTemplate::kCalledOnNonObject,
+                              isolate->factory()->NewStringFromAsciiChecked(
+                                  "Reflect.isExtensible")));
+  }
+
+  Maybe<bool> result =
+      JSReceiver::IsExtensible(Handle<JSReceiver>::cast(target));
+  MAYBE_RETURN(result, ReadOnlyRoots(isolate).exception());
+  return *isolate->factory()->ToBoolean(result.FromJust());
+}
+
 // ES6 section 26.1.11 Reflect.ownKeys
 BUILTIN(ReflectOwnKeys) {
   HandleScope scope(isolate);

src/builtins/reflect.tq

-// Copyright 2019 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.
-
-namespace reflect {
-
-  const kCalledOnNonObject: constexpr MessageTemplate
-  generates 'MessageTemplate::kCalledOnNonObject';
-
-  // ES6 section 26.1.10 Reflect.isExtensible
-  transitioning javascript builtin ReflectIsExtensible(
-      implicit context: Context)(receiver: Object, object: Object): Object {
-    const objectJSReceiver = Cast<JSReceiver>(object)
-        otherwise ThrowTypeError(kCalledOnNonObject, 'Reflect.isExtensible');
-    return object::ObjectIsExtensible(objectJSReceiver);
-  }
-}  // namespace reflect