Creates the hash_seed byte array in RO_SPACE and moves the root from
STRONG_MUTABLE_IMMOVABLE_ROOT_LIST to STRONG_READ_ONLY_ROOT_LIST.

Bug: v8:8191
Change-Id: I3b044fbb3e51eb5d21ac2e68a54076623865b9d2
Reviewed-on: https://chromium-review.googlesource.com/c/1297959
Commit-Queue: Dan Elphick <delphick@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56960}