In preparation for allowing Torque to generate the list of instance
types, I'd like to make the rules a bit more consistent for how instance
types are spelled. This CL is my proposal for a system where every
non-String instance type name is exactly equal to calling
CapifyStringWithUnderscores on the corresponding class name and
appending "_TYPE".

This change is almost all find&replace; the only manual changes are in:
- src/objects/instance-type.h
- src/torque/utils.cc
- tools/gen-postmortem-metadata.py

This change is in response to the review comment
https://chromium-review.googlesource.com/c/v8/v8/+/1757094/25/src/builtins/base.tq#132

Change-Id: Ife3857292669f54931708e934398b2684e60bea5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1814888
Commit-Queue: Seth Brenith <seth.brenith@microsoft.com>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Reviewed-by: Frank Tang <ftang@chromium.org>
Cr-Commit-Position: refs/heads/master@{#64199}