Fix another const bug in function.  Thanks to Daniel Krugler for finding this and the previous bug.

llvm-svn: 113686
diff --git a/libcxx/include/functional b/libcxx/include/functional
index b9378aa..3cc21d4 100644
--- a/libcxx/include/functional
+++ b/libcxx/include/functional
@@ -1141,9 +1141,9 @@
 
     // deleted overloads close possible hole in the type system
     template<class _R2, class... _ArgTypes2>
-      bool operator==(const function<_R2(_ArgTypes2...)>&) = delete;
+      bool operator==(const function<_R2(_ArgTypes2...)>&) const = delete;
     template<class _R2, class... _ArgTypes2>
-      bool operator!=(const function<_R2(_ArgTypes2...)>&) = delete;
+      bool operator!=(const function<_R2(_ArgTypes2...)>&) const = delete;
 public:
     // function invocation:
     _R operator()(_ArgTypes...) const;