[libc++] Fix failing concepts tests
diff --git a/libcxx/test/std/concepts/lang/same_as.pass.cpp b/libcxx/test/std/concepts/lang/same_as.pass.cpp
index c41d6c4..76e019d 100644
--- a/libcxx/test/std/concepts/lang/same_as.pass.cpp
+++ b/libcxx/test/std/concepts/lang/same_as.pass.cpp
@@ -7,6 +7,7 @@
//===----------------------------------------------------------------------===//
// UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+// UNSUPPORTED: libcpp-no-concepts
// template<class T, class U>
// concept same_as;