This CL removes a build script that was used to create ANTLR visitors
for Torque parsing. As Torque rolls its own parser now, this script
can safely be removed.

R=tebbi@chromium.org

Bug: v8:9183
Change-Id: Id56ee590d79e5c849ac111e8825cd3733cd55d90
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1587379Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Commit-Queue: Simon Zünd <szuend@chromium.org>
Cr-Commit-Position: refs/heads/master@{#61069}