Most dead variable warnings in GCMole are false positives, either from
failing to detect that TryEvacuateObject returning false means it didn't
allocate, or a regex error thinking that GarbageCollectionReasonToString
causes garbage collection (because the mangled version is something like
GarbageCollectionReasonToString[...]GarbageCollectionReason, and that
matches /Collect.*Garbage/).

Update the whitelist and fix the "Collect.*Garbage" regex to only look
at the function name.

Bug: v8:9985
Change-Id: I62284e97e4975a6a87616d1d535b2ac7958d17bb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1989829
Auto-Submit: Leszek Swirski <leszeks@chromium.org>
Reviewed-by: Maya Lekova <mslekova@chromium.org>
Commit-Queue: Leszek Swirski <leszeks@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65622}