[libc++] Mark <chrono> test as unsupported on AppleClang 9

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@368914 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/std/utilities/time/time.hms/hhmmss.fail.cpp b/test/std/utilities/time/time.hms/hhmmss.fail.cpp
index 8849831..4e76d4c 100644
--- a/test/std/utilities/time/time.hms/hhmmss.fail.cpp
+++ b/test/std/utilities/time/time.hms/hhmmss.fail.cpp
@@ -6,6 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 // UNSUPPORTED: c++98, c++03, c++11, c++14, c++17
+// UNSUPPORTED: apple-clang-9
 // <chrono>
 
 // template <class Duration> class hh_mm_ss;