[builtins] Fix -Wshadow warnings

Bug: v8:12244,v8:12245
Change-Id: I02e08e79a7b3a07531bfac753beff13a866247e8
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3269170Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Zhi An Ng <zhin@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77878}

src/builtins/builtins-async-generator-gen.cc

@@ -381,7 +381,6 @@ TF_BUILTIN(AsyncGeneratorAwaitCaught, AsyncGeneratorBuiltinsAssembler) {
 }
 
 TF_BUILTIN(AsyncGeneratorResumeNext, AsyncGeneratorBuiltinsAssembler) {
-  using Descriptor = AsyncGeneratorResumeNextDescriptor;
   const auto generator =
       Parameter<JSAsyncGeneratorObject>(Descriptor::kGenerator);
   const auto context = Parameter<Context>(Descriptor::kContext);
@@ -542,7 +541,6 @@ TF_BUILTIN(AsyncGeneratorResolve, AsyncGeneratorBuiltinsAssembler) {
 }
 
 TF_BUILTIN(AsyncGeneratorReject, AsyncGeneratorBuiltinsAssembler) {
-  using Descriptor = AsyncGeneratorRejectDescriptor;
   const auto generator =
       Parameter<JSAsyncGeneratorObject>(Descriptor::kGenerator);
   const auto value = Parameter<Object>(Descriptor::kValue);