This changes the compare/exchange operation to the 'strong' one
which avoids potential spurious failures. These failures would be
hidden by the loop in AtomicGuard - except that we only ever call
compare_exchange_weak once when is_blocking is false. See the linked
bug for more info.

Bug: v8:8649
Change-Id: I94ebe04e86f4676d2b7404d833157f61d5df8a59
Reviewed-on: https://chromium-review.googlesource.com/c/1418190Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Alexei Filippov <alph@chromium.org>
Commit-Queue: Peter Marshall <petermarshall@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58909}