This is a reland of 33fa357b

TBR=mvstanton@chromium.org

Original change's description:
> Do not use FixedDoubleArray to store RNG state
>
> Also:
>  - replace runtime call with cheaper C call
>  - change state to double conversion
>
> R=mvstanton@chromium.org
>
> Bug: v8:8212
> Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
> Change-Id: If4bfe0f5fb1864c89f4acd871cb8b74c7cd7ab09
> Reviewed-on: https://chromium-review.googlesource.com/1240116
> Commit-Queue: Yang Guo <yangguo@chromium.org>
> Reviewed-by: Michael Stanton <mvstanton@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#56165}

Bug: v8:8212
Change-Id: Iccc9128034ce7b65801a04a54982219b5a4fe84e
Cq-Include-Trybots: luci.chromium.try:linux_chromium_rel_ng
Reviewed-on: https://chromium-review.googlesource.com/1238551Reviewed-by: Yang Guo <yangguo@chromium.org>
Commit-Queue: Yang Guo <yangguo@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56175}