This makes message reporting use the same message text for the normal
as well as --predictable execution. Running in predictable mode should
just suppress all asm.js messages wholesale if needed.

R=clemensh@chromium.org

Change-Id: Ice1e83c4b098fbc4c3b301c685614afe26190016
Reviewed-on: https://chromium-review.googlesource.com/506093Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#45368}