We cannot emit the constant pool within the safepoint table data. It
seems like we also don't do that, but the forgotten
{BlockConstPoolScope} triggered a DCHECK.

R=leszeks@chromium.org

Bug: chromium:1227351, chromium:1217074
Change-Id: I187004c83e05002c651a15643bddea5b02cb00c3
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3015559Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Clemens Backes <clemensb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#75657}