add local hacks to get libc building on arm

Going in the wrong direction here, but then again it's good to
gain more perspective before feeding things into NetBSD.
NetBSD src for "user", checkout.sh rev d8e66017298692b9e4e44279641f3159d4f7a38c
Merge branch 'user-src-clean' into user-src
Merge branches 'kernel-src' and 'user-src' into all-src