Bad type error message with parameterized types

[catamorphism]

This code:

use std;
import std::option;

fn bad() {
  let @option::t[int] rz = foo[uint]();
}

fn foo[ZZZ]() -> @option::t[ZZZ] {
  fail;
}

fails with a type error:
error: mismatched types: expected @option::t[int] but found @option::t[ZZZ] (types differ)

This is a bad error message because it refers to a line inside bad() -- in this scope, ZZZ is meaningless. The error should say uint instead of ZZZ.

[msullivan]

This seems to be fixed.