Suggest .clone() when we have &T, T was expected and T: Clone

[estebank]

Given

#[derive(Clone)]
struct S;
fn foo(_: S) {}
fn main() {
    let s = &S;
    foo(s);
}

we should suggest cloning.

Also, given

#[derive(Clone)]
struct S;
trait X {}
impl X for S {}
fn foo<T: X>(_: T) {}
fn bar<T: X>(s: &T) {
    foo(s);
}
fn main() {}

we should suggest

fn bar<T: X + Clone>(s: &T) {
    foo(s.clone());
}

[chenyukang]

@rustbot claim

[chenyukang]

If we suggest add Clone bound, we don't need struct S dervie Clone,
This code will compile:

struct S;
trait X {}
impl X for S {}
fn foo<T: X>(_: T) {}
fn bar<T: X + Clone>(s: &T) {
    foo(s.clone());
}