The atomics and compare-exchange stress tests are intended to test
code generation only anyway and can be quite slow. So skip all the
variants.

Notry: true
Change-Id: Idf443b134558990c7eac43301fa816399794b9d5
Reviewed-on: https://chromium-review.googlesource.com/c/1291077
Commit-Queue: Michael Achenbach <machenbach@chromium.org>
Reviewed-by: Michael Achenbach <machenbach@chromium.org>
Cr-Commit-Position: refs/heads/master@{#56820}