We should not use -I/usr/include/machine. That is not the right way

to fix the endian.h inclusion problem in mcom_db.h.  We should fix
mcom_db.h to say:
#ifdef __osf__
#include <machine/endian.h>
#endif
Using -I/usr/include/machine will pull in <machine/signal.h>, which
is incompatible with the intended <signal.h>.

config/OSF1.mk

@@ -27,7 +27,7 @@ ARCH			:= dec
 CPU_ARCH		:= alpha
 GFX_ARCH		:= x
 
-OS_INCLUDES		= -I/usr/include/machine
+OS_INCLUDES		=
 G++INCLUDES		=
 LOC_LIB_DIR		= /usr/lib/X11
 MOTIF			=