bootstrap broken on Solaris

[Raymond Meyer <raymond.meyer%rambler.ru@localhost>]

Have there recently been any modifications to the way bmake is built? It seem
to be broken on Solaris:

rm -f bmake *.[ado] */*.[ado] .*.done .depend
/scripts/compiler_wrappers/gcc -g -O2  -I../../libnbcompat -c  
/opt/pkg.obj/bmake/arch.c
In file included from /opt/pkg.obj/bmake/arch.c:153:
/opt/pkg.obj/bmake/make.h:99:23: error: sys/cdefs.h: No such file or directory