We need to push the sign-extended constant instead of just the lower 32
bits. Otherwise, the callee might read stale data from the stack.

Bug: chromium:854011, v8:6600

R=ahaas@chromium.org
CC=rodolph.perfetta@arm.com

Change-Id: Iafcfd6ba9532771615b41215fb4d1a2b85ce5623
Reviewed-on: https://chromium-review.googlesource.com/1124683Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#54185}