assertion did match the conditions under which this method gets called
(Runtime_DateCurrentTime). The bug got introduced as part of this change:
https://codereview.chromium.org/802333002

The assertion crash can be reproduced using:
% out/Debug/d8 --prof -e 'new Date();'

R=jkummerow@chromium.org
BUG=

Review URL: https://codereview.chromium.org/1104303002

Cr-Commit-Position: refs/heads/master@{#28096}