This is a reland of edab8730
It was speculatively reverted but the issue turned out to just be slow
tests.

Original change's description:
> Fix -Wimplicit-int-float-conversions.
>
> Bug: chromium:989932
> Change-Id: Ief917b023cb079f5ff87dc8963d74f225d074d7a
> Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2989096
> Reviewed-by: Bill Budge <bbudge@chromium.org>
> Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
> Auto-Submit: Peter Kasting <pkasting@chromium.org>
> Commit-Queue: Peter Kasting <pkasting@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#75413}

Bug: chromium:989932
Change-Id: Iec8ac8ee32705c6a699a2df2f292ffe07cde99f7
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2994802Reviewed-by: Bill Budge <bbudge@chromium.org>
Reviewed-by: Sigurd Schneider <sigurds@chromium.org>
Commit-Queue: Bill Budge <bbudge@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75443}