Phase 2 of the great MachineRegisterInfo cleanup.  This time, we're changing
operator* on the by-operand iterators to return a MachineOperand& rather than
a MachineInstr&.  At this point they almost behave like normal iterators!

Again, this requires making some existing loops more verbose, but should pave
the way for the big range-based for-loop cleanups in the future.

llvm-svn: 203865
diff --git a/llvm/lib/CodeGen/OptimizePHIs.cpp b/llvm/lib/CodeGen/OptimizePHIs.cpp
index 748a59c..50968ef 100644
--- a/llvm/lib/CodeGen/OptimizePHIs.cpp
+++ b/llvm/lib/CodeGen/OptimizePHIs.cpp
@@ -139,8 +139,8 @@
   if (PHIsInCycle.size() == 16)
     return false;
 
-  for (MachineRegisterInfo::use_iterator I = MRI->use_begin(DstReg),
-         E = MRI->use_end(); I != E; ++I) {
+  for (MachineRegisterInfo::use_instr_iterator I = MRI->use_instr_begin(DstReg),
+         E = MRI->use_instr_end(); I != E; ++I) {
     MachineInstr *UseMI = &*I;
     if (!UseMI->isPHI() || !IsDeadPHICycle(UseMI, PHIsInCycle))
       return false;