R600: Fix for Unigine when MachineSched is enabled

Fixes for-loop.cl piglit test

Patch By: Vincent Lejeune

Reviewed-by: Tom Stellard <thomas.stellard@amd.com>

NOTE: This is a candidate for the Mesa stable branch.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175742 91177308-0d34-0410-b5e6-96231b3b80d8