This fixes the validation of "|0" annotations of call sites that are
used to indicate a "signed" return type of functions. We use lookahead
during call validation and request deferred validation as part of the
actual OR-expression. Special care has to be taken to get precedence
levels of all involved operators right.

R=clemensh@chromium.org
TEST=mjsunit/asm/call-annotation
BUG=v8:6183

Change-Id: If0586f669e7cee26a13425b0fd9f41098e852d68
Reviewed-on: https://chromium-review.googlesource.com/475871
Commit-Queue: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44639}