Improve error behaviour in test case

[philberty]

I tried this code: https://godbolt.org/z/9jE9ozo5M

I already have this fix in phil/dev as its making our coercion sites closer to rustc.

struct Foo<A> { 
    a: A,                                                        
}                                      
                                                                    
impl Foo<isize> {    
    fn bar(self) -> isize {                                
        self.a
    }                                               
}

impl Foo<char> {
    fn bar(self) -> char {
        self.a
    }
}

impl<T> Foo<T> {
    fn bar(self) -> T {
        self.a
    }
}

fn main() {
    let a = Foo { a: 123 };
    a.bar();
}

I expected to see this happen:

$ rustc test.rs
error[E0592]: duplicate definitions with name `bar`
  --> test.rs:6:5
   |
6  |     fn bar(self) -> isize {
   |     ^^^^^^^^^^^^^^^^^^^^^ duplicate definitions for `bar`
...
18 |     fn bar(self) -> T {
   |     ----------------- other definition for `bar`

error[E0592]: duplicate definitions with name `bar`
  --> test.rs:12:5
   |
12 |     fn bar(self) -> char {
   |     ^^^^^^^^^^^^^^^^^^^^ duplicate definitions for `bar`
...
18 |     fn bar(self) -> T {
   |     ----------------- other definition for `bar`

Instead, this happened:

<source>:25:7: error: multiple candidates found for method 'bar'
    6 |     fn bar(self) -> isize {
      |     ~~ 
......
   18 |     fn bar(self) -> T {
      |     ~~ 
......
   25 |     a.bar();
      |       ^~~
<source>:25:5: error: failed to type resolve expression
   25 |     a.bar();
      |     ^

Meta

• What version of Rust GCC were you using, git sha if possible. 0d4a447

[philberty]

this looks to be fixed