POSIX: add _SC_TTY_NAME_MAX

Change-Id: Ifa24f68535d7a4a4c5fe3f01e63fe2c87adcc429
Reviewed-on: https://review.haiku-os.org/c/haiku/+/3340
Reviewed-by: Jérôme Duval <jerome.duval@gmail.com>

headers/posix/unistd.h

@@ -135,6 +135,7 @@
 #define _SC_REGEXP						62
 #define _SC_SYMLOOP_MAX					63
 #define _SC_SHELL						64
+#define _SC_TTY_NAME_MAX				65
 
 
 /* confstr() constants */

src/system/libroot/posix/unistd/conf.cpp

@@ -87,6 +87,8 @@ __sysconf(int name)
 			return STREAM_MAX;
 		case _SC_SYMLOOP_MAX:
 			return SYMLOOP_MAX;
+		case _SC_TTY_NAME_MAX:
+			return TTY_NAME_MAX;
 		case _SC_TZNAME_MAX:
 			return TZNAME_MAX;
 		case _SC_VERSION: