Second part of P0482 - char8_t. Reviewed as https://reviews.llvm.org/D55308

llvm-svn: 348828
diff --git a/libcxx/include/limits b/libcxx/include/limits
index 5b75f4a9..5ea9a9e 100644
--- a/libcxx/include/limits
+++ b/libcxx/include/limits
@@ -119,6 +119,7 @@
 
 _LIBCPP_PUSH_MACROS
 #include <__undef_macros>
+#include <version>
 
 
 _LIBCPP_BEGIN_NAMESPACE_STD