We check that if we do not get a result, or if we get a negative result,
then there has to be a scheduled exception.

R=clemensh@chromium.org
TEST=mjsunit/regress/wasm/regression-704127
BUG=chromium:704127

Change-Id: I3fef3cc02f685a9cbc3f10203e2a59b61b3702d5
Reviewed-on: https://chromium-review.googlesource.com/458282Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44144}