x86 flang buildbot status (it almost works!)

Greetings,

I've not been able to attend flang calls recently due to a recurring
conflict, but wanted to provide an update on the x86 buildbot at
Berkeley Lab.

The entire pipeline now succeeds except for a single clang unittest,
`DirectoryWatcherTest`. It seems to be sensitive to the kind of file
system it runs on. I have filed this bug report in bugzilla:
46825 – clang DirectoryWatcherTest unittest hangs on some filesystems, but not others. If I filed that bug under
the wrong category (I chose LLVM lit), please feel free to reassign, I
wasn't quite sure where to put it.

I do have a temporary workaround which makes this test pass reliably
(set TMPDIR to a GPFS file system, since all others seem to hang). But
I would like not to have to rely on these kinds of workarounds in
general.

Thanks to Galina for helping get this buildbot this far. It's almost there!