swift234

Remove binary "nix" introduced in commit 94ebcb847b3aae799da1cdb9374ad090f75d86dc

$ file nix
nix: Mach-O 64-bit x86_64 executable

$ git log nix
commit 94ebcb847b3aae799da1cdb9374ad090f75d86dc
Author: John McCall <rjmccall@apple.com>
Date:   Tue Jan 12 23:34:54 2016 -0800

    Handle inherited concrete conformances correctly on witness_method instructions.

    rdar://24141848