Implement union layout support.

llvm-svn: 76846
diff --git a/clang/lib/CodeGen/CGRecordLayoutBuilder.h b/clang/lib/CodeGen/CGRecordLayoutBuilder.h
index ac2f53c..c1ba605 100644
--- a/clang/lib/CodeGen/CGRecordLayoutBuilder.h
+++ b/clang/lib/CodeGen/CGRecordLayoutBuilder.h
@@ -83,6 +83,9 @@
   /// Layout - Will layout a RecordDecl.
   void Layout(const RecordDecl *D);
 
+  /// LayoutUnion - Will layout a union RecordDecl.
+  void LayoutUnion(const RecordDecl *D);
+  
   /// LayoutField - try to layout all fields in the record decl.
   /// Returns false if the operation failed because the struct is not packed.
   bool LayoutFields(const RecordDecl *D);