On intel platforms, floats do not always have a stable bit pattern.
To preserve the bit pattern of float immediates, we should keep them
in an int using get_bits() instead of casting them to a float with
get_scalar().

R=ahaas@chromium.org
CC=​zhin@chromium.org

Change-Id: I481219f755c40cbba760be5744734c1075e8ab66
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2172694
Commit-Queue: Thibaud Michaud <thibaudm@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67560}