Merge r323039 into the 6.0 branch

[llvmbot]

Bugzilla Link	36027
Resolution	FIXED
Resolved on	Jan 22, 2018 07:09
Version	6.0
OS	OpenBSD
Blocks	#35152
Reporter	LLVM Bugzilla Contributor
CC	@zmodem

Extended Description

Please merge r323039 to implement __clear_cache() for OpenBSD/mips64.

[zmodem]

Merged in r323120.