In preparation for upcoming work on Torque function pointers.

This table will be used to look up the entry address in order to call
there directly without going through the (on-heap) trampoline.

Bug: v8:7777
Change-Id: If713430c843e85371a5aaef8a3bfb5da9e0ea903
Reviewed-on: https://chromium-review.googlesource.com/c/1378172Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Jakob Gruber <jgruber@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58245}