If the embedder specifies an initial heap size, then we can take it
as a hint to skip full GCs below that threshold.

Bug: v8:9306
Change-Id: I42a4c597bf75c6ba9845ed7a6bd9946012979005
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1646515Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#62030}