In order to make loop header aligned at 64 byte (relative to memory address), code start should also be aligned at 64 byte.

Bug: chromium:1231471
Change-Id: I95390babd9cc78492e0beb0f1b03901eb481d5d5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3094167Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Hao A Xu <hao.a.xu@intel.com>
Cr-Commit-Position: refs/heads/main@{#76484}