This ensures that large object has exactly the size of a regular page.
Avoids wasting memory due to alignment.

Bug: v8:10315
Change-Id: Ife8051313f1ea8c1fc0ba0afcc4e5db11f27adca
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2335191Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#69225}