Ok, an AssertingVH definitely doesn't work for now because we free our cache after the optimizer may have hacked on the module. Use a WeakVH instead.

llvm-svn: 82324
diff --git a/clang/lib/CodeGen/CGDebugInfo.h b/clang/lib/CodeGen/CGDebugInfo.h
index d0f0731..b796b1e 100644
--- a/clang/lib/CodeGen/CGDebugInfo.h
+++ b/clang/lib/CodeGen/CGDebugInfo.h
@@ -49,7 +49,7 @@
 
   /// TypeCache - Cache of previously constructed Types.
   // FIXME: Eliminate this map.  Be careful of iterator invalidation.
-  std::map<void *, llvm::AssertingVH<llvm::MDNode> > TypeCache;
+  std::map<void *, llvm::WeakVH> TypeCache;
 
   bool BlockLiteralGenericSet;
   llvm::DIType BlockLiteralGeneric;