Add TABDLY, TAB0, TAB3 for better source compatibility.

These are XSI extensions but some code seems to expect them.
We don't currently implement TAB1 or TAB2.  Idea from FreeBSD.
OK guenther@ gnezdo@

diff --git a/sys/sys/termios.h b/sys/sys/termios.h
index af21a97..681c294 100644 (file)
--- a/sys/sys/termios.h
+++ b/sys/sys/termios.h
@@ -1,4 +1,4 @@
-/*     $OpenBSD: termios.h,v 1.13 2016/09/20 21:10:22 fcambus Exp $    */
+/*     $OpenBSD: termios.h,v 1.14 2022/12/30 23:41:45 millert Exp $    */
 /*     $NetBSD: termios.h,v 1.14 1996/04/09 20:55:41 cgd Exp $ */
 
 /*
@@ -111,10 +111,15 @@
 #if __XPG_VISIBLE
 #define ONLCR          0x00000002      /* map NL to CR-NL (ala CRMOD) */
 #endif
+#if __BSD_VISIBLE || __XPG_VISIBLE
+#define TABDLY         0x00000004      /* horizontal tab delay mask */
+#define TAB0           0x00000000      /* no tab delay or expansion */
+#define TAB3           0x00000004      /* expand tabs to spaces */
 #if __BSD_VISIBLE
-#define OXTABS         0x00000004      /* expand tabs to spaces */
+#define OXTABS         TAB3            /* BSD name for TAB3 */
 #define ONOEOT         0x00000008      /* discard EOT's (^D) on output */
 #endif
+#endif
 #if __XPG_VISIBLE
 #define OCRNL          0x00000010      /* map CR to NL */
 #define OLCUC          0x00000020      /* translate lower case to upper case */