This happened on an attempt to compile a kernel on arch-i386, kernel
sup'ed as of this morning.

cc  -O2 -Werror -I. -I../../../../arch -I../../../.. -DI486_CPU -DI586_CPU -DXSERVER -DUCONSOLE -DINSECURE -DMACHINE_NONCONTIG -DTIMEZONE="0x12c" -DDST="0" -DSWAPPAGER -DVNODEPAGER -DDEVPAGER -DDDB -DDIAGNOSTIC -DKTRACE -DSYSVMSG -DSYSVSEM -DSYSVSHM -DCOMPAT_NOMID -DCOMPAT_09 -DCOMPAT_10 -DCOMPAT_43 -DTCP_COMPAT_42 -DCOMPAT_SVR4 -DCOMPAT_IBCS2 -DCOMPAT_LINUX -DCOMPAT_FREEBSD -DLKM -DFFS -DMFS -DCD9660 -DMSDOSFS -DFDESC -DFIFO -DKERNFS -DNULLFS -DPORTAL -DPROCFS -DUMAPFS -DUNION -DINET -DGENERIC -D_KERNEL -Di386  -c ../../../../arch/i386/i386/machdep.c
../../../../arch/i386/i386/machdep.c:1426: parse error before `bus_chipset_tag_t'
cc1: warnings being treated as errors
../../../../arch/i386/i386/machdep.c:1426: warning: data definition has no type or storage class
../../../../arch/i386/i386/machdep.c:1427: parse error before `bpa'
../../../../arch/i386/i386/machdep.c:1427: warning: data definition has no type or storage class
../../../../arch/i386/i386/machdep.c:1428: parse error before `size'
../../../../arch/i386/i386/machdep.c:1428: warning: data definition has no type or storage class
../../../../arch/i386/i386/machdep.c:1430: parse error before `*'
../../../../arch/i386/i386/machdep.c:1430: warning: data definition has no type or storage class
../../../../arch/i386/i386/machdep.c:1431: parse error before `{'
../../../../arch/i386/i386/machdep.c:1435: initializer element is not constant
../../../../arch/i386/i386/machdep.c:1435: warning: data definition has no type or storage class
../../../../arch/i386/i386/machdep.c:1436: initializer element is not constant
../../../../arch/i386/i386/machdep.c:1436: warning: data definition has no type or storage class
../../../../arch/i386/i386/machdep.c:1438: conflicting types for `va'
../../../../arch/i386/i386/machdep.c:1433: previous declaration of `va'
../../../../arch/i386/i386/machdep.c:1438: initializer element is not constant
../../../../arch/i386/i386/machdep.c:1438: warning: data definition has no type or storage class
../../../../arch/i386/i386/machdep.c:1439: parse error before `if'
../../../../arch/i386/i386/machdep.c:1441: warning: initialization from incompatible pointer type
../../../../arch/i386/i386/machdep.c:1441: initializer element is not constant
../../../../arch/i386/i386/machdep.c:1441: warning: data definition has no type or storage class
../../../../arch/i386/i386/machdep.c:1443: parse error before `for'
../../../../arch/i386/i386/machdep.c:1457: parse error before `bus_chipset_tag_t'
../../../../arch/i386/i386/machdep.c:1457: warning: data definition has no type or storage class
../../../../arch/i386/i386/machdep.c:1458: parse error before `memh'
../../../../arch/i386/i386/machdep.c:1458: warning: data definition has no type or storage class
../../../../arch/i386/i386/machdep.c:1459: parse error before `size'
../../../../arch/i386/i386/machdep.c:1459: warning: data definition has no type or storage class
../../../../arch/i386/i386/machdep.c:1463: redefinition of `va'
../../../../arch/i386/i386/machdep.c:1438: `va' previously defined here
../../../../arch/i386/i386/machdep.c:1463: initializer element is not constant
../../../../arch/i386/i386/machdep.c:1463: warning: data definition has no type or storage class
../../../../arch/i386/i386/machdep.c:1464: initializer element is not constant
../../../../arch/i386/i386/machdep.c:1464: warning: data definition has no type or storage class
../../../../arch/i386/i386/machdep.c:1465: parse error before `-'
../../../../arch/i386/i386/machdep.c:1465: conflicting types for `kmem_free'
../../../../vm/vm_extern.h:74: previous declaration of `kmem_free'
../../../../arch/i386/i386/machdep.c:1465: warning: data definition has no type or storage class
*** Error code 1

Stop.