Verify that one of the ranges produced by region splitting is allocatable.

We should not be attempting a region split if it won't lead to at least one
directly allocatable interval. That could cause infinite splitting loops.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124893 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed