Fix C++14 CI

Author: ldionne

libcxx/test/libcxx/input.output/filesystems/class.directory_entry/directory_entry.mods/last_write_time.pass.cpp

@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++03, c++11
+// UNSUPPORTED: c++03, c++11, c++14
 // UNSUPPORTED: availability-filesystem-missing
 // UNSUPPORTED: no-filesystem
 // ADDITIONAL_COMPILE_FLAGS: -I %S/../../../../../../src

libcxx/test/libcxx/input.output/filesystems/convert_file_time.pass.cpp

@@ -6,7 +6,7 @@
 //
 //===----------------------------------------------------------------------===//
 
-// UNSUPPORTED: c++03, c++11
+// UNSUPPORTED: c++03, c++11, c++14
 // UNSUPPORTED: availability-filesystem-missing
 
 // <filesystem>