After cooking relibc, copy the freshly built libc.a and libc.so to both
the prefix toolchain and the redoxer toolchain (the latter is what
'make live' actually consumes for cross-recipe builds).
Without this, recipes that link against the dynamic libc.so see a stale
copy (no eventfd, no __fseterr, ...) and fail with 'undefined reference'
at link time. 'make prefix' does this sync via its sysroot rule, but
'make r.relibc' alone does not — covering both paths prevents the
first recipe that needs a new symbol from breaking the build.
vasilito
3c6f2bf301