Include explicit (de)referencing in E0283

[eggyal]

Given the following code (playground):

use std::borrow::Borrow;

fn main() {
    let v = vec![0];
    v.borrow();
}

The current output is:

error[E0283]: type annotations needed
 --> src/main.rs:5:7
  |
5 |     v.borrow();
  |     --^^^^^^--
  |     | |
  |     | cannot infer type for type parameter `Borrowed` declared on the trait `Borrow`
  |     this method call resolves to `&Borrowed`
  |     help: use the fully qualified path for the potential candidate: `<Vec<T> as Borrow<[T]>>::borrow(v)`
  |
  = note: cannot satisfy `Vec<i32>: Borrow<_>`

Ideally the output should look like:

error[E0283]: type annotations needed
 --> src/main.rs:5:7
  |
5 |     v.borrow();
  |     --^^^^^^--
  |     | |
  |     | cannot infer type for type parameter `Borrowed` declared on the trait `Borrow`
  |     this method call resolves to `&Borrowed`
  |     help: use the fully qualified path for the potential candidate: `<Vec<T> as Borrow<[T]>>::borrow(&v)`
  |
  = note: cannot satisfy `Vec<i32>: Borrow<_>`

The compiler already determined that the v needed to be deref coerced to &Borrowed but then suggested invoking ::borrow(v) which obviously won't type check; it should suggest invoking ::borrow(&v) instead (and likewise for the mutable case). If dereferencing was required in the method resolution, then that should also be included in the suggestion: ::borrow(&**v) etc.

@rustbot label: A-coercions A-diagnostics A-inference -C-enhancement C-bug D-invalid-suggestion

[estebank]

Current output:

error[[E0283]](https://doc.rust-lang.org/stable/error_codes/E0283.html): type annotations needed
 --> src/main.rs:5:7
  |
5 |     v.borrow();
  |       ^^^^^^
  |
  = note: multiple `impl`s satisfying `Vec<i32>: Borrow<_>` found in the following crates: `alloc`, `core`:
          - impl<T, A> Borrow<[T]> for Vec<T, A>
            where A: Allocator;
          - impl<T> Borrow<T> for T
            where T: ?Sized;
help: try using a fully qualified path to specify the expected types
  |
5 |     <Vec<i32> as Borrow<Borrowed>>::borrow(&v);
  |     ++++++++++++++++++++++++++++++++++++++++ ~

It should be

help: try using a fully qualified path to specify the expected types
  |
5 |     <Vec<i32> as Borrow<[i32]>>::borrow(&v);
  |     ++++++++++++++++++++++++++++++++++++++++ ~