Fix sbrk to actually return the *old* break.
Created by: ProgVal
I also added a test that fails before this patch but succeeds after.
This PR also fixes the following issue in relibc: https://github.com/redox-os/relibc/issues/83
Created by: ProgVal
I also added a test that fails before this patch but succeeds after.
This PR also fixes the following issue in relibc: https://github.com/redox-os/relibc/issues/83