AMDGPU: Fix not accounting for tail call resource usage

If the only call in a function is a tail call, the
function isn't considered to have a call since it's a
type of return.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@312561 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed