AMDGPU: Make AllocationPriority of SGPRs higher than VGPRs

Since SGPRs should spill to VGPRs, they should be allocated first.
I don't think this is sufficient for SGPRs to always spill to
VGPRs though.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@289671 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed