Autocomplete for deref doesn't work for structs defined inside a function

[cbrewster]

Example:

use std::rc::Rc;

fn main() {
    struct Foo {
        a: i32,
        b: String,
    }

    let foo = Rc::new(Foo {
        a: 1,
        b: "Hello!".into(),
    });

    foo.<|>
}

Expected:
The autocomplete at foo.<|> should show options for fields a and b.

Actual:
The autocomplete options do not include any of the fields from Foo.

[flodiebold]

Duplicate of #1559, I don't think this has anything to do with the deref.