Create a new function kind for initializer functions and ban arguments
if used in such a function.

Bug: v8:5367, v8:7183
Cq-Include-Trybots: luci.v8.try:v8_linux_noi18n_rel_ng
Change-Id: Id3089e587b3d6a25f27224045f250e032b831818
Reviewed-on: https://chromium-review.googlesource.com/850547
Commit-Queue: Sathya Gunasekaran <gsathya@chromium.org>
Reviewed-by: Adam Klein <adamk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#50369}