This adds a test-preparser cctest corresponding to the regression test added in
https://chromium-review.googlesource.com/865900

BUG=chromium:801772

Change-Id: I33d74e242fd765b91b7c148b9a0af4960a7b05ea
Reviewed-on: https://chromium-review.googlesource.com/870311Reviewed-by: Adam Klein <adamk@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50688}