E0623 not working for below examples

[gaurikholkar-zz]

Example 1

struct Foo;

impl Foo {
    fn foo(&self, v: &mut Vec<&u32>, x: &u32) {
        v.push(x);
    }
}

Example 2

fn foo(v: &mut Vec<&u32>, x: &u32) {
    v.push(x);
}

Example 3

struct Foo;

impl Foo {
    fn foo(&self, x: &u32) -> &u32 {
        x
    }
}

cc @nikomatsakis

[gaurikholkar-zz]

first two work now, third one will be fixed in an ongoing PR.

[gaurikholkar-zz]

Waiting for #44124 to merge

[arielb1]

Merged in #44936.

[estebank]

I believe the current output is reasonable for all the presented cases.