Cannot import same impls from two numeric types at once

[bstrie]

There are three impls in int-template.rs and uint-template.rs that apply to all numeric types. Until recently, if you tried to do this:

import int::num;
import i8::num;

you'd receive "error: duplicate definition of type num". d14d415 fixed this for the particular case of the num impl, but trying to duplicate the process for the eq and ord impls gives weird errors in libstd/sort.rs that I'm hoping the resolve rewrite will, er, resolve. It won't be possible to automatically export the eq and ord impls on numeric types until this is fixed.

[brson]

I've done some poking and can't get away from 'duplicate definition of eq' errors.

[catamorphism]

I'll consider this blocked on #1935

[bstrie]

Fixed by new resolve.