mod std can't import option::t as option then re-export it

[brson]

I've just tried this in std:

import option = option::t;
export option;

and it gets this error

../src/lib/std.rs:2:0: 2:25 error: unresolved modulename: option
../src/lib/std.rs:2 import option = option::t;

There's a workaround, but I think this is probably the pattern we want to work for raising types like option::t out of their modules.

[brson]

Thanks for fixing this marijnh (I wish github would notify my when the bugs I file are closed).