Use MachineInstr::mop_iterator instead of MIOperands; NFC

(Const)?MIOperands is equivalent to the C++ style
MachineInstr::mop_iterator. Use the latter for consistency except for a
few callers of MIOperands::analyzePhysReg().

llvm-svn: 285029
diff --git a/llvm/lib/CodeGen/MachinePipeliner.cpp b/llvm/lib/CodeGen/MachinePipeliner.cpp
index 516296c..37455c5 100644
--- a/llvm/lib/CodeGen/MachinePipeliner.cpp
+++ b/llvm/lib/CodeGen/MachinePipeliner.cpp
@@ -1726,9 +1726,9 @@
     const MachineInstr *MI = SU->getInstr();
     if (MI->isPHI())
       continue;
-    for (ConstMIOperands MO(*MI); MO.isValid(); ++MO)
-      if (MO->isReg() && MO->isUse()) {
-        unsigned Reg = MO->getReg();
+    for (const MachineOperand &MO : MI->operands())
+      if (MO.isReg() && MO.isUse()) {
+        unsigned Reg = MO.getReg();
         if (TargetRegisterInfo::isVirtualRegister(Reg))
           Uses.insert(Reg);
         else if (MRI.isAllocatable(Reg))
@@ -1737,9 +1737,9 @@
       }
   }
   for (SUnit *SU : NS)
-    for (ConstMIOperands MO(*SU->getInstr()); MO.isValid(); ++MO)
-      if (MO->isReg() && MO->isDef() && !MO->isDead()) {
-        unsigned Reg = MO->getReg();
+    for (const MachineOperand &MO : SU->getInstr()->operands())
+      if (MO.isReg() && MO.isDef() && !MO.isDead()) {
+        unsigned Reg = MO.getReg();
         if (TargetRegisterInfo::isVirtualRegister(Reg)) {
           if (!Uses.count(Reg))
             LiveOutRegs.push_back(RegisterMaskPair(Reg, 0));