* Implement liboverride.o to provide overrides of various libc functions.
For now, compile a special version of rcmd(3) (et al) which uses
/rescue/rcmd and /rescue/sh instead of the /bin variants.
Other overrides may appear in the future.
Should fix [bin/21670] from Geoff Wing.
on those, no fix has been forthcoming, and users are getting antsy.
This allows "make build" to complete; "make release" will still fail in the
sets generation. Maybe *that* will inspire a MIPS/toolchain guru to fix
crunchgen(1)...