Make %PretenureAllocationSite more resilient to fuzzer inputs/configs
and allow it for fuzzing.

Bug: chromium:1200724
Change-Id: I541b1410ab1719b478c4ad9516dc350fec02fbba
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2883783Reviewed-by: Dominik Inführ <dinfuehr@chromium.org>
Commit-Queue: Patrick Thier <pthier@chromium.org>
Cr-Commit-Position: refs/heads/master@{#74479}