Summary:
This patch adds support for __builtin_dcbf for PPC.
__builtin_dcbf copies the contents of a modified block from the data cache
to main memory and flushes the copy from the data cache.
Differential revision: https://reviews.llvm.org/D59843
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@359517 91177308-0d34-0410-b5e6-96231b3b80d8
Ahsan Saghir