Also should address minor performance regressions for instance types
that should (and used to) use map compare rather than instance_type
comparison.

In the process, convert a bunch of IsXXX methods from the CSA into
exported Torque methods that call through to the Cast<> to ensure
there is only a single implementation of the type checkers. Also clean
up and remove duplicate/redundant code and unused Torque imports.

Bug: v8:7793, chromium:1098481
Change-Id: I3cd5146d913bb75bab4f73415b1b94bc30924725
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2270545
Commit-Queue: Daniel Clifford <danno@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#68621}