The regexp parser historically has tried to gracefully detect and bail
out from excess zone allocations, where 'excess' was determined to be
an arbitrary limit of 256MB.

This leads to issues now that the regexp parser may run from within
the JS parser - the JS parser doesn't observe this arbitrary limit and
happily keeps allocating until the underlying allocator actually runs
out of memory; this way, the JS parser can handle very large JS files,
and it's now counterproductive if the regexp parser (which reuses the
JS parser zone) bails out on excess allocations.

This CL simply removes the excess_allocation mechanism.

Bug: chromium:1264014
Change-Id: I8d93a1e52aa65bb0ea6c2aab3b68b479ce79a1f6
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3401580Reviewed-by: Toon Verwaest <verwaest@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/main@{#78991}