Remove dead metadata.

llvm-svn: 78651
diff --git a/llvm/lib/VMCore/LLVMContextImpl.h b/llvm/lib/VMCore/LLVMContextImpl.h
index 3d1f3b2..245aa4a 100644
--- a/llvm/lib/VMCore/LLVMContextImpl.h
+++ b/llvm/lib/VMCore/LLVMContextImpl.h
@@ -105,7 +105,10 @@
   
   ValueMap<char, Type, ConstantAggregateZero> AggZeroConstants;
 
-  ValueMap<std::vector<Value*>, Type, MDNode, true /*largekey*/> MDNodes;
+  typedef ValueMap<std::vector<Value*>, Type, MDNode, true /*largekey*/> 
+  MDNodeMapTy;
+
+  MDNodeMapTy MDNodes;
   
   typedef ValueMap<std::vector<Constant*>, ArrayType, 
     ConstantArray, true /*largekey*/> ArrayConstantsTy;