This CL ensures we care only about our internal pointer types and not
about raw C++ pointers, because normally special care is taken when
storing raw pointers to the managed heap. Furthermore, checking for raw
pointers produces too many false positives in the dead variable
analysis.

Bug: v8:9680, chromium:1000635
Change-Id: Ica9ea1fe09b7456c011910a6886149b6dfdda1f5
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1924357
Commit-Queue: Maya Lekova <mslekova@chromium.org>
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Reviewed-by: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65174}