The typed function references proposal allows an optional second
parameter to Table.grow containing the initialization value for the
newly added entries for tables that do not support null defaults.

This CL adds this functionality but hides it behind a newly added
experimental flag --experimental-wasm-typed-funcref.

R=ahaas@chromium.org
CC=jkummerow@chromium.org
CC=manoskouk@chromium.org

Bug: v8:9495
Change-Id: Ia156aeacf95bc36a9fc182990f315c42075cbb7b
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2207184
Commit-Queue: Emanuel Ziegler <ecmziegler@chromium.org>
Reviewed-by: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#67900}