PR #209999 (9e2e9b33e1) "broke" the GPU
build by causing many/most tests to not run.
The follow-up in #210715 (4bd1a447e1)
broke it for real
(https://lab.llvm.org/buildbot/#/builders/10/builds/32254) by causing
too many tests to run.
I think we just need to disable the extra tests, but I want to start out
by reverting both patches so that it's easier to compare the
before/after state in the next attempt.
b7f642fdb2