Make allocator comparison const in allocator_traits test

test/unordered/allocator_traits.cpp

@@ -36,8 +36,8 @@
   {                                                                            \
     return (std::numeric_limits<std::size_t>::max)();                          \
   }                                                                            \
-  bool operator==(name<T> const&) { return true; }                             \
-  bool operator!=(name<T> const&) { return false; }                            \
+  bool operator==(name<T> const&) const { return true; }                       \
+  bool operator!=(name<T> const&) const { return false; }                      \
 /**/
 
 #define ALLOCATOR_METHODS_TYPEDEFS(name)                                       \