Rustdoc doesn't document impls within functions

[Manishearth]

You probably shouldn't be doing this, but given that you can, we should try and support it

pub struct Foo;

pub fn foo() {
    impl Foo {
        pub fn bar(&self) {
        }
    }
}

bar() is not documented, despite being usable globally. This might have to do with --everybody-loops?.

This works fine for trait implementations.

[ollie27]

Duplicate of #53763