We add support for i31.new, i31.get_u and i31.get_s to the fuzzed module.

Bug: v8:11954
Change-Id: Ic6cdb5ced1b56507083d91e5c0c7f21d59a18acf
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3218980Reviewed-by: Thibaud Michaud <thibaudm@chromium.org>
Reviewed-by: Manos Koukoutos <manoskouk@chromium.org>
Commit-Queue: Maria Tîmbur <mtimbur@google.com>
Cr-Commit-Position: refs/heads/main@{#77354}