SetCodeModificationPermissions better reflects its current usage.

Change-Id: Ia9b42328a2d467613736878e2b560e0d5282ad3f
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3173674Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77015}