Revert: [MachineScheduler] Fix for PR21807: minor code difference building with/without -g.

Test 'misched-code-difference-with-debug.ll' was failing on some buildbots.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@224121 91177308-0d34-0410-b5e6-96231b3b80d8