AMDGPU/SI: Don't handle a loop if there is no loop at all for a terminator BB.

Differential Revision: http://reviews.llvm.org/D22021

Reviewed by: arsenm

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@277073 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed