llvm dev - May 2019 - Flaky MergeICmps/X86 test on llvm-clang-x86_64-expensive-checks-win

It looks like there's a flaky test, maybe someone who understands
the relevant area can take a closer look.  I noticed because the
same failure showed up twice as blame mail from my recent series
of commits.  This test:

llvm/test/Transforms/MergeICmps/X86/entry-block-shuffled.ll

will sometimes fail on llvm-clang-x86_64-expensive-checks-win.
I don't claim any expertise but the intervening commits don't
really look like they would cause or fix these failures.

Build #
17607    pass (although another test failed)
17608    pass
17609    FAIL
17610    FAIL
17611    pass
17612    pass
17613    FAIL
17614    pass
17615    pass
17616    FAIL
17617    FAIL
17618    pass
17619    pass

See for example
http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-win/builds/17613

Thanks,
--paulr