This fixes the fall-back case when parsing a multiplicative expression
where the lookahead found a '-' token followed by an unsigned token, but
no '*' token is following. We cannot rewind both tokens, but still need
to make sure that a full multiplicative expression is parsed.

R=clemensh@chromium.org
TEST=mjsunit/regress/regress-8377
BUG=v8:8377

Change-Id: I20ce6267445b32bdaf03f41f11d9ef4be66cb636
Reviewed-on: https://chromium-review.googlesource.com/c/1304317Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#57084}