This CL add decoding and code generation for the table.grow
instruction. For code generation we just generate a runtime
call. The implementation is quite straight-forward. However,
I did several small cleanups along the way. I hope it's still
acceptable. I could also split out some cleanups into separate
CLs.

R=mstarzinger@chromium.org

Bug: v8:7581
Change-Id: Id885b7e70eb4f5bccfe779eb216f7cc9302ea3a5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1593078
Commit-Queue: Andreas Haas <ahaas@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61192}