Merge r280672, per bug 30839:

  Add support for targeting armv6-unknown-cloudabi-eabihf.

  I'm in the progress of adding ARMv6 support to CloudABI. On the compiler
  side, everything seems to work properly with this tiny change applied.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/branches/release_39@287093 91177308-0d34-0410-b5e6-96231b3b80d8