move "include" to "xen/include"

All of mini-os is more or less under xen/ now.
fix minios include path
Add __libc_static_tls_setup() as a nop

To be called by the next src-netbsd libc
update buildrump.sh for subr::stdlibs()
use stdlibs()
update buildrump.sh and use new subr.sh syntax