Macro 'USE_SIMULATOR' should wrap the whole v8::internal namespace.

Change-Id: I2b0102e563b6cb976e5a450363bc770f8d5628e2
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1916439
Auto-Submit: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65069}