This is the same treatment we give other numeric literals, and seems
sensible since they end up referenced from Ignition's constant pool.

R=jkummerow@chromium.org

Bug: v8:6791
Change-Id: Ia689c709d402e4e87b7d2d22c582108400c25580
Reviewed-on: https://chromium-review.googlesource.com/922283
Commit-Queue: Adam Klein <adamk@chromium.org>
Reviewed-by: Jakob Kummerow <jkummerow@chromium.org>
Reviewed-by: Hannes Payer <hpayer@chromium.org>
Cr-Commit-Position: refs/heads/master@{#51409}