Add protection from min/max macros

llvm-svn: 145407
diff --git a/libcxx/include/memory b/libcxx/include/memory
index 878dda8..7576aaeb 100644
--- a/libcxx/include/memory
+++ b/libcxx/include/memory
@@ -600,6 +600,8 @@
     #include <cassert>
 #endif
 
+#include <__undef_min_max>
+
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif