Fix __clear_cache declaration.

This fixes the build with gcc in gnu++98 and gnu++11 mode.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181811 91177308-0d34-0410-b5e6-96231b3b80d8
Temporarily revert "Subtract isn't commutative, fix this for MMX psub."

It's causing failures on the atom bot.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181812 91177308-0d34-0410-b5e6-96231b3b80d8
Reapply "Subtract isn't commutative, fix this for MMX psub." with
a somewhat randomly chosen cpu that will minimize cpu specific
differences on bots.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181814 91177308-0d34-0410-b5e6-96231b3b80d8
Hexagon: Pass to replace tranfer/copy instructions into combine instruction
where possible.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181817 91177308-0d34-0410-b5e6-96231b3b80d8