- Fixes the size check to include Code::kHeaderSize.
- Adds a DCHECK in NewEmptyCode.

Bug: v8:11872
Change-Id: I05156bbe42e7efa8aa0e1982c9e2166d7b09ef5b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3015055
Auto-Submit: Victor Gomes <victorgomes@chromium.org>
Commit-Queue: Dominik Inführ <dinfuehr@chromium.org>
Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75643}