New spec changes allow anyref tables to be initialized with function
references.

R=mstarzinger@chromium.org

Bug: v8:7581
Change-Id: I59596e1e383408114b974fa10529ae15b8cf7a15
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1627348Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61823}