[ergonomic private brand checks] Fix private name lookup in proxies

Runtime_HasProperty already does the right thing; this CL is directing
more cases to it.

Bug: v8:12580
Change-Id: I16ae6099fa9781ecc663085e87a7fc59abd10d02
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3422639Reviewed-by: Igor Sheludko <ishell@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78850}

src/codegen/code-stub-assembler.cc

@@ -13419,7 +13419,7 @@ TNode<Oddball> CodeStubAssembler::HasProperty(TNode<Context> context,
     TNode<Name> name = CAST(CallBuiltin(Builtin::kToName, context, key));
     switch (mode) {
       case kHasProperty:
-        GotoIf(IsPrivateSymbol(name), &return_false);
+        GotoIf(IsPrivateSymbol(name), &call_runtime);
 
         result = CAST(
             CallBuiltin(Builtin::kProxyHasProperty, context, object, name));

test/mjsunit/regress/regress-12580.js

+// Copyright 2022 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.
+
+class Foo extends function () {
+    return new Proxy(Object.create(new.target.prototype), {}); } {
+  #bar = 7;
+  has() { return #bar in this; }
+};
+
+assertTrue((new Foo()).has());