(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/examples/Kaleidoscope/Chapter7/toy.cpp b/examples/Kaleidoscope/Chapter7/toy.cpp
index e63578f..4070d3f 100644
--- a/examples/Kaleidoscope/Chapter7/toy.cpp
+++ b/examples/Kaleidoscope/Chapter7/toy.cpp
@@ -752,6 +752,7 @@
   Builder.SetInsertPoint(MergeBB);
   PHINode *PN = Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()),
                                   "iftmp");
+  PN->reserveOperandSpace(2);
   
   PN->addIncoming(ThenV, ThenBB);
   PN->addIncoming(ElseV, ElseBB);