acpica/acfreebsd.h bug with boot code (stand.h)

[Andrey Chernov]

/usr/src/sys/contrib/dev/acpica/acfreebsd.h includes ctype.h which is 
incompatible with its redefinition in /usr/include/stand.h

As result we got:
===> i386/libi386
cc -O -pipe -march=pentium3 -ffreestanding -DCOMPORT=0x3f8 -DCOMSPEED=9600 
-DTERM_EMU -I/usr/src/sys/boot/i386/libi386/../../common 
-I/usr/src/sys/boot/i386/libi386/../btx/lib  
-I/usr/src/sys/boot/i386/libi386/../../../contrib/dev/acpica  
-I/usr/src/sys/boot/i386/libi386/../../.. -I. 
-I/usr/src/sys/boot/i386/libi386/../../../../lib/libstand/ -ffreestanding 
-mpreferred-stack-boundary=2   -c 
/usr/src/sys/boot/i386/libi386/biosacpi.c
In file included from /usr/src/sys/contrib/dev/acpica/acfreebsd.h:165,
                 from /usr/src/sys/boot/i386/libi386/biosacpi.c:33:
/usr/include/ctype.h:88: syntax error before "int"
*** Error code 1

Please fix it somehow.