CodeGen: Remove implicit ilist iterator conversions, NFC

Finish removing implicit ilist iterator conversions from LLVMCodeGen.
I'm sure there are lots more of these in lib/CodeGen/*/.

llvm-svn: 249915
diff --git a/llvm/lib/CodeGen/VirtRegMap.cpp b/llvm/lib/CodeGen/VirtRegMap.cpp
index 507729a..bf992a1 100644
--- a/llvm/lib/CodeGen/VirtRegMap.cpp
+++ b/llvm/lib/CodeGen/VirtRegMap.cpp
@@ -355,7 +355,7 @@
     DEBUG(MBBI->print(dbgs(), Indexes));
     for (MachineBasicBlock::instr_iterator
            MII = MBBI->instr_begin(), MIE = MBBI->instr_end(); MII != MIE;) {
-      MachineInstr *MI = MII;
+      MachineInstr *MI = &*MII;
       ++MII;
 
       for (MachineInstr::mop_iterator MOI = MI->operands_begin(),