Each valid memory module generated by one of the wasm fuzzers will now
also be executed in Liftoff, and the result of the execution will be
compared against the interpreted result.

R=ahaas@chromium.org

Bug: v8:6600
Change-Id: I6a437faae4230ce4dfc7924dd1418da20ea92356
Reviewed-on: https://chromium-review.googlesource.com/753328Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#49154}