iam propose all the architecture move in a separate directory
as is done in openbsd and netbsd
ie
#mkdir /usr/src/sys/arch
#mv -R /usr/src/sys/{amd64,arm,i386,ia64,mips,pc98,powerpc,sparc64,sun4v,xen,x86) /usr/src/sys/arch/
Would it ever done in freebsd?