(Almost) always call reserveOperandSpace() on newly created PHINodes.

llvm-svn: 128535
diff --git a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
index bf32741..f9641c6 100644
--- a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -1039,6 +1039,7 @@
 
   // Insert new integer induction variable.
   PHINode *NewPHI = PHINode::Create(Int32Ty, PN->getName()+".int", PN);
+  NewPHI->reserveOperandSpace(2);
   NewPHI->addIncoming(ConstantInt::get(Int32Ty, InitValue),
                       PN->getIncomingBlock(IncomingEdge));