Merging r351360:

Merging r351360:
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r351360 | jmorse | 2019-01-16 18:41:29 +0100 (Wed, 16 Jan 2019) | 6 lines

Add a REQUIRES: darwin line for a mac test.

This test, apparently for macs, fails on Windows as lit can't emulate
the shell subprocess $(which...) correctly. Some other netbsd and linux
buildbots also fail here. Limit to macs as a temporary workaround.

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git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_80@351419 91177308-0d34-0410-b5e6-96231b3b80d8