There is only one legitimate use remaining, in addIntervalsForSpills().
All other calls to hasPHIKill() are only used to update PHIKill flags.
The addIntervalsForSpills() function is part of the old spilling
framework, only used by linearscan.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139783 91177308-0d34-0410-b5e6-96231b3b80d8