Cannot compile for powerpc-unknown-linux-gnu

[Caleb Zulawski]

I get the error:

  = note: error: unable to find or provide libc for target 'powerpc-linux.3.16...5.10.81-gnu.2.19'
          info: zig can provide libc for related target powerpc-linux-gnueabi
          info: zig can provide libc for related target powerpc-linux-gnueabihf
          info: zig can provide libc for related target powerpc-linux-musl

I'm guessing the target needs to be translated to gnueabi or gnueabihf.

[messense]

Pull requests are welcome.