The new flags enum had kReduceMemory as the first value, which means it
got the value 0 and thus was considered as never set.

Bug: v8:12407, chromium:1274954
Change-Id: Ifcce2316c1dcd09a12ad52ef391f513b014aea1c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3310609Reviewed-by: Michael Lippautz <mlippautz@chromium.org>
Commit-Queue: Omer Katz <omerkatz@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78189}