Add TIOCPKT and TIOCSPTLCK to the Linuxolator.

We're very lucky, because the flags used by our TIOCPKT implementation
are the same as flags used by Linux. We can safely enable TIOCPKT,
assuming EXTPROC is not used.

TIOCSPTLCK is used by unlockpt(). Because we don't need unlockpt() in
our implementation, make this ioctl a no-op.

Approved by:	philip (mentor, implicit), rdivacky
Obtained from:	P4 (//depot/projects/mpsafetty/...)

sys/compat/linux/linux_ioctl.c

@@ -893,7 +893,10 @@ linux_ioctl_termio(struct thread *td, struct linux_ioctl_args *args)
 		break;
 	}
 
-	/* LINUX_TIOCPKT */
+	case LINUX_TIOCPKT:
+		args->cmd = TIOCPKT;
+		error = (ioctl(td, (struct ioctl_args *)args));
+		break;
 
 	case LINUX_FIONBIO:
 		args->cmd = FIONBIO;
@@ -993,6 +996,10 @@ linux_ioctl_termio(struct thread *td, struct linux_ioctl_args *args)
 			    sizeof(int));
 		break;
 	}
+	case LINUX_TIOCSPTLCK:
+		/* Our unlockpt() does nothing. */
+		error = 0;
+		break;
 	default:
 		error = ENOIOCTL;
 		break;

sys/compat/linux/linux_ioctl.h

@@ -368,6 +368,7 @@
 #define	LINUX_TIOCCBRK		0x5428
 
 #define LINUX_TIOCGPTN		0x5430
+#define LINUX_TIOCSPTLCK	0x5431
 
 #define	LINUX_FIONCLEX		0x5450
 #define	LINUX_FIOCLEX		0x5451