imported modules aren't exported

[marijnh]

If I have, in mod1:

import foo = x.y;

And then in another mod try to refer to mod1.foo.[something], I get (with rustboot) "error: the name 'foo' can't be found in the module".

Maybe this is by design, but I'd argue that it'd be very good to have this supported (and that it's not hard to support). I ran into this trying to factor out the duplicated native modules in lib/linux_os.rs and lib/macosx_os.rs.

[graydon]

Supported in rustc; buggy in rustboot. Unfortunately I don't think we can easily fix it in rustboot. Need to stick with either redundant declarations or compiler-conditional crate components until after we bootstrap.