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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128535 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/BreakCriticalEdges.cpp b/lib/Transforms/Utils/BreakCriticalEdges.cpp
index 616b066..3384cb6 100644
--- a/lib/Transforms/Utils/BreakCriticalEdges.cpp
+++ b/lib/Transforms/Utils/BreakCriticalEdges.cpp
@@ -142,6 +142,7 @@
     // Otherwise a new PHI is needed. Create one and populate it.
     PHINode *NewPN = PHINode::Create(PN->getType(), "split",
                                      SplitBB->getTerminator());
+    NewPN->reserveOperandSpace(Preds.size());
     for (unsigned i = 0, e = Preds.size(); i != e; ++i)
       NewPN->addIncoming(V, Preds[i]);
     // Update the original PHI.