Add protection from min/max macros

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@145407 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/vector b/include/vector
index 7f7e3d3..10702f3 100644
--- a/include/vector
+++ b/include/vector
@@ -270,6 +270,8 @@
 #include <__split_buffer>
 #include <__functional_base>
 
+#include <__undef_min_max>
+
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #pragma GCC system_header
 #endif