The `Self` type is not monomorphized correctly

[nikomatsakis]

The following variation on default-method-simple dies with an ICE:

// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

#[allow(default_methods)];

fn boop<'a, T>(x: &'a T) -> &'a T { x }

trait Foo {
    fn f(&self) {
        io::println("Hello!");
        boop(self).g();
    }
    fn g(&self);
}

struct A {
    x: int
}

impl Foo for A {
    fn g(&self) {
        io::println("Goodbye!");
    }
}

pub fn main() {
    let a = A { x: 1 };
    a.f();
}

the reason for this is that the call to boop requires an auto-ref, and when we evaluate a def_self we get back ty_self, which never gets substititued. I have some theories on how best to fix this :) but for now I am just tagging it and adding some workarounds to the patch on the borrow checker (search for FIXMEs)

[sanxiyn]

No ICE any more. Fixed by #7545?

[pnkfelix]

Seems to be fixed indeed. Closing.