assume_aligned allows the caller may assume alignment of the allocation
methods.

Bug: v8:12295
Change-Id: I0c946dd668ae9c0c1d83da7278ad8d87bab96717
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3218984
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Anton Bikineev <bikineev@chromium.org>
Cr-Commit-Position: refs/heads/main@{#77366}