Currently mksnapshot fails due to ubsan issues. With a nosnap build it
will be easier to track down failures initially as normal test
failures, since mksnapshot isn't called with the sanitizer
environment variables.

NOTRY=true
TBR=jgruber@chromium.org

Bug: v8:7860
Change-Id: I897a8d307d90f545c80a90e1e1a2a632ffae1c3e
Reviewed-on: https://chromium-review.googlesource.com/1116783Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54051}