During GC fuzzing we combine multiple tests and run them inside
a wrapper that needs to ignore all errors/exceptions/asserts to
keep the combined tests running. We will use this flag to ignore
%AbortJS calls.

Bug: v8:6917
Change-Id: Ib426a68228cadbea8364c5e1d29c39dd53129481
Reviewed-on: https://chromium-review.googlesource.com/857514Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michał Majewski <majeski@google.com>
Cr-Commit-Position: refs/heads/master@{#50768}