In the process, also fix the make-torque-parser.py script to work in its new
location.

Bug: v8:7793
Change-Id: I376a5f73ec9f7cc87995928397c6e399b1a490d8
Reviewed-on: https://chromium-review.googlesource.com/1084838
Commit-Queue: Daniel Clifford <danno@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#53504}