DebugInfo: Don't create duplicate forward declaration metadata unnecessarily.

No functionality change, at best a slight (questionable) optimization,
but necessary for correctness of future work.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@188474 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGDebugInfo.h b/lib/CodeGen/CGDebugInfo.h
index 68cc690..3a0d07f 100644
--- a/lib/CodeGen/CGDebugInfo.h
+++ b/lib/CodeGen/CGDebugInfo.h
@@ -305,9 +305,9 @@
 
   llvm::DIScope getCurrentContextDescriptor(const Decl *Decl);
 
-  /// createRecordFwdDecl - Create a forward decl for a RecordType in a given
-  /// context.
-  llvm::DIType createRecordFwdDecl(const RecordDecl *, llvm::DIDescriptor);
+  /// \brief Create a forward decl for a RecordType in a given context.
+  llvm::DICompositeType getOrCreateRecordFwdDecl(const RecordDecl *,
+                                                 llvm::DIDescriptor);
 
   /// createContextChain - Create a set of decls for the context chain.
   llvm::DIDescriptor createContextChain(const Decl *Decl);