Pinned registers were not considered correctly when taking a volatile
register. This CL refactors handling of the pinned registers list by
combining the candidates list and the pinned list early. This avoid
additional parameters on some functions and might save some redundant
masking.
As a side effect, it also fixes the DCHECK error on arm.

R=ahaas@chromium.org

Bug: chromium:1179025
Change-Id: Ib9193b209c5741ea97fd1d0dffeeb9e824639439
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/2699254Reviewed-by: Andreas Haas <ahaas@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#72812}