Loong64 supports 4K-64K OS pages
Fix loong64 unittests PlatformUsesGuardPages failure

Change-Id: I1451685828ef1d857b7d2af3f1810286f84bdc50
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3299672Reviewed-by: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn>
Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Zhao Jiazhong <zhaojiazhong-hf@loongson.cn>
Cr-Commit-Position: refs/heads/main@{#78120}