misched prep: rename InsertPos to End.

ScheduleDAGInstrs knows nothing about how instructions will be moved or inserted.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152256 91177308-0d34-0410-b5e6-96231b3b80d8

lib/CodeGen/MachineScheduler.cpp

@@ -226,7 +226,7 @@ void ScheduleTopDownLive::schedule() {
       releaseNode(&(*I));
   }
 
-  InsertPos = Begin;
+  MachineBasicBlock::iterator InsertPos = Begin;
   while (SUnit *SU = pickNode()) {
     DEBUG(dbgs() << "*** Scheduling Instruction:\n"; SU->dump(this));