[Support] Bring std::errc::not_supported to llvm::errc.

llvm-svn: 338114

llvm/include/llvm/Support/Errc.h

@@ -63,6 +63,7 @@ enum class errc {
   no_such_process = int(std::errc::no_such_process),
   not_a_directory = int(std::errc::not_a_directory),
   not_enough_memory = int(std::errc::not_enough_memory),
+  not_supported = int(std::errc::not_supported),
   operation_not_permitted = int(std::errc::operation_not_permitted),
   permission_denied = int(std::errc::permission_denied),
   read_only_file_system = int(std::errc::read_only_file_system),