We can't properly guarantee that the interrupt is served from inside
the irregexp engine (it could happen before or after). Without that
guarantee, the test is prone to flaking. It's not very useful in
general, since it essentially only tests that the
CHECK(!regexp_stack_->is_in_use()) in regexp-stack.cc exists.

The real fix is to support reentrancy.

Bug: v8:11435,v8:11382
Change-Id: I0a8c3313dd9285ac0c84fef867196dede4785ebb
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2752159
Auto-Submit: Jakob Gruber <jgruber@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#73362}