PLEASE NOTE: IF YOU APPLY THIS PATCH AND PLAN TO UPGRADE FROM 1.3.3 TO 1.3.4
             VIA PATCHES TOO, SAVE THIS PATCHFILE AND DO A REVERT PATCH
             BEFORE APPLYING THE 1.3.4 PATCH, AS THIS PROBLEM WILL BE FIXED
             IN 1.3.4.

From John Darrow <John.P.Darrow@wheaton.edu> posted to port-i386@netbsd.org:

Compiling a kernel with COMPAT_IBCS2 and VM86 from a clean 1.3.3 source tree
fails due to a missing include of <machine/vm86.h>.  This problem first
showed up in 1.3.2 and was send-pr'ed twice.  The first pr (kern/5574)
was closed 19981218 by Jason Thorpe with the commend 'Fixed.'  The second
pr (port-i386/5884) is still open, and was just (19981228) reassigned to
port-i386-maintainer.  However, the fix doesn't appear to have been
pulled up properly, as the 1.3.3 syssrc tarball contains the same version
of sys/arch/i386/i386/ibcs2_machdep.c (v 1.3.2.2) as 1.3.2 had.

--- src/sys/arch/i386/i386/ibcs2_machdep.c-orig-1.3.2.2	Tue Jun  2 11:09:24 1998
+++ src/sys/arch/i386/i386/ibcs2_machdep.c	Mon Jan  4 12:42:52 1999
@@ -54,6 +54,11 @@
 
 #include <compat/ibcs2/ibcs2_signal.h>
 
+
+#ifdef VM86
+#include <machine/vm86.h>
+#endif
+
 void
 ibcs2_setregs(p, epp, stack)
 	struct proc *p;