Xing Xue:  port to IBM XLC++/AIX.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@188396 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/algorithm b/include/algorithm
index adf820f..053b809 100644
--- a/include/algorithm
+++ b/include/algorithm
@@ -628,6 +628,10 @@
 #include <iterator>
 #include <cstddef>
 
+#if defined(__IBMCPP__)
+#include "support/ibm/support.h"
+#endif
+
 #include <__undef_min_max>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)