Fix undefined behavior (binding a reference to a dereferenced null pointer) if
SSAUpdater was created and destroyed without being initialized.

llvm-svn: 162137
diff --git a/llvm/lib/Transforms/Utils/SSAUpdater.cpp b/llvm/lib/Transforms/Utils/SSAUpdater.cpp
index e568a61..72d4199 100644
--- a/llvm/lib/Transforms/Utils/SSAUpdater.cpp
+++ b/llvm/lib/Transforms/Utils/SSAUpdater.cpp
@@ -39,7 +39,7 @@
   : AV(0), ProtoType(0), ProtoName(), InsertedPHIs(NewPHI) {}
 
 SSAUpdater::~SSAUpdater() {
-  delete &getAvailableVals(AV);
+  delete static_cast<AvailableValsTy*>(AV);
 }
 
 /// Initialize - Reset this object to get ready for a new set of SSA