Until now, the cross-over mutator would choke on several expressions
from DB and bail out (just wastes some time). We also have a script,
test_db.js to test on how many expressions it is going to bail out.

With this change, we already omit adding such expressions to the
DB in the first place. As a result, the test_db script now returns
zero failing expressions (while all other expressions remain).

Regression tests that now no longer apply are removed, instead a
test is added that ensures that a failing expression isn't added
to the DB.

No-Try: true
Bug: chromium:1044942
Change-Id: I14a4fe802c99114cf3a8f71188273475a7cb9c13
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/3129340Reviewed-by: Liviu Rau <liviurau@chromium.org>
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/main@{#76598}