Fix libc_pic.a

In order to support coverage binaries and non-coverage binaries with libraries,
separate libraries need to be created which don't have coverage symbols (and
dependent symbols on libc) in them. libc_pic.a for instance will not link with
binaries if it's compiled with --coverage.

This allows buildworld to complete, minus rtld-elf -- it's a special snowflake
that needs to be resolved with a solution that I don't yet possess.