R600: Use address space enum instead of value

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210966 91177308-0d34-0410-b5e6-96231b3b80d8
R600: Fix asserts related to constant initializers

This would assert if a constant address space was extern
and therefore didn't have an initializer. If the initializer
was undef, it would hit the unreachable unhandled initializer case.

An extern global should never really occur since we don't have
machine linking, but bugpoint likes to remove initializers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210967 91177308-0d34-0410-b5e6-96231b3b80d8
Fix typo

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210968 91177308-0d34-0410-b5e6-96231b3b80d8
R600: Add failing testcases.

These are reduced from assert in the
OpenCV CvtColor8u.BGR5652GRAY test.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210969 91177308-0d34-0410-b5e6-96231b3b80d8