Reworking and adding a node type would require also adding
parallelization support for minor mc. Since this is unused and not
benchmarked right now, just remove it.

Bug: chromium:923361
Change-Id: Iaf67a743d76d2b37ffff9961b510bfd8a1bd15ff
Reviewed-on: https://chromium-review.googlesource.com/c/1425900
Commit-Queue: Michael Lippautz <mlippautz@chromium.org>
Reviewed-by: Ulan Degenbaev <ulan@chromium.org>
Cr-Commit-Position: refs/heads/master@{#58993}