Update LLVM for 3.5 rebase (r209712).

Change-Id: I149556c940fb7dc92d075273c87ff584f400941f
diff --git a/lib/CodeGen/PHIElimination.cpp b/lib/CodeGen/PHIElimination.cpp
index 0e9df58..c8d0819 100644
--- a/lib/CodeGen/PHIElimination.cpp
+++ b/lib/CodeGen/PHIElimination.cpp
@@ -13,7 +13,6 @@
 //
 //===----------------------------------------------------------------------===//
 
-#define DEBUG_TYPE "phielim"
 #include "llvm/CodeGen/Passes.h"
 #include "PHIEliminationUtils.h"
 #include "llvm/ADT/STLExtras.h"
@@ -35,6 +34,8 @@
 #include <algorithm>
 using namespace llvm;
 
+#define DEBUG_TYPE "phielim"
+
 static cl::opt<bool>
 DisableEdgeSplitting("disable-phi-elim-edge-splitting", cl::init(false),
                      cl::Hidden, cl::desc("Disable critical edge splitting "
@@ -377,7 +378,7 @@
       findPHICopyInsertPoint(&opBlock, &MBB, SrcReg);
 
     // Insert the copy.
-    MachineInstr *NewSrcInstr = 0;
+    MachineInstr *NewSrcInstr = nullptr;
     if (!reusedIncoming && IncomingReg) {
       if (SrcUndef) {
         // The source register is undefined, so there is no need for a real
@@ -531,13 +532,14 @@
 /// used later to determine when the vreg is killed in the BB.
 ///
 void PHIElimination::analyzePHINodes(const MachineFunction& MF) {
-  for (MachineFunction::const_iterator I = MF.begin(), E = MF.end();
-       I != E; ++I)
-    for (MachineBasicBlock::const_iterator BBI = I->begin(), BBE = I->end();
-         BBI != BBE && BBI->isPHI(); ++BBI)
-      for (unsigned i = 1, e = BBI->getNumOperands(); i != e; i += 2)
-        ++VRegPHIUseCount[BBVRegPair(BBI->getOperand(i+1).getMBB()->getNumber(),
-                                     BBI->getOperand(i).getReg())];
+  for (const auto &MBB : MF)
+    for (const auto &BBI : MBB) {
+      if (!BBI.isPHI())
+        break;
+      for (unsigned i = 1, e = BBI.getNumOperands(); i != e; i += 2)
+        ++VRegPHIUseCount[BBVRegPair(BBI.getOperand(i+1).getMBB()->getNumber(),
+                                     BBI.getOperand(i).getReg())];
+    }
 }
 
 bool PHIElimination::SplitPHIEdges(MachineFunction &MF,
@@ -546,7 +548,7 @@
   if (MBB.empty() || !MBB.front().isPHI() || MBB.isLandingPad())
     return false;   // Quick exit for basic blocks without PHIs.
 
-  const MachineLoop *CurLoop = MLI ? MLI->getLoopFor(&MBB) : 0;
+  const MachineLoop *CurLoop = MLI ? MLI->getLoopFor(&MBB) : nullptr;
   bool IsLoopHeader = CurLoop && &MBB == CurLoop->getHeader();
 
   bool Changed = false;
@@ -563,7 +565,7 @@
       // out-of-line blocks into the loop which is very bad for code placement.
       if (PreMBB == &MBB && !SplitAllCriticalEdges)
         continue;
-      const MachineLoop *PreLoop = MLI ? MLI->getLoopFor(PreMBB) : 0;
+      const MachineLoop *PreLoop = MLI ? MLI->getLoopFor(PreMBB) : nullptr;
       if (IsLoopHeader && PreLoop == CurLoop && !SplitAllCriticalEdges)
         continue;