This is a reland of c6c9d4bf

Original change's description:
> Update unicode-regexp-ignore-case-noi18n expectations
> 
> There appear to be one or several bugs in noi18n mode such that
> expectations in this test are no longer met. This CL updates
> expectations to the current behavior and re-enables the test so we at
> least preserve coverage in the other cases.
> 
> The behavior in question should be investigated in the future
> (low priority).
> 
> Bug: v8:10120
> Change-Id: Ib7c9a18133a386e6e39ee54d68ce4106d9b28c84
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2081815
> Commit-Queue: Jakob Gruber <jgruber@chromium.org>
> Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#66524}

Bug: v8:10120
Change-Id: Ib2ee68e26c2aebe2eeab3ec9f7bc263fd79f3773
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2083291
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Cr-Commit-Position: refs/heads/master@{#66550}