Arm64 jumbo builds might otherwise select the CountTrailingZeros function
from utils-arm64.h as a closer match, and fail to build due to differences
in the function prototype.

Bug: chromium:782640
Change-Id: Ie26d71b34aaf0e3ae5020597fed506df83b7d0ea
Reviewed-on: https://chromium-review.googlesource.com/758271Reviewed-by: Clemens Hammacher <clemensh@chromium.org>
Commit-Queue: Mostyn Bramley-Moore <mostynb@vewd.com>
Cr-Commit-Position: refs/heads/master@{#49226}