Type inference goes in the wrong direction

[Vlad-Shcherbina]

To reproduce

1. Open the following program in VSCode:

   // [dependencies]
   // rand = "0.7"
   
   fn main() {
       use rand::seq::SliceRandom;
       let (x, y) = [(1, 2)].choose(&mut rand::thread_rng()).unwrap();
       let x: i32 = x;
   }

2. Mouse hover over x in let (x, y) = ....

Expected result

The inferred type should be &i32.
Alternatively, if we accept Chalk limitations or whatever this is, {unknown}.

Actual result

The inferred type is i32.
This makes the error in the next line confusing.

By the way, the inferred type of y is {unknown}.
Removing the next line turns the inferred type of x into {unknown} as well.

rust-analyzer version: 2020-05-25 (fbb8b88)

[lnicola]

Duplicate of #1165.

Inferring x as i32 is normal, the compiler does the same thing every time you write Vec::new().

[flodiebold]

Type inference after type errors is best-effort; we infer x as i32 from the subsequent usage to still give you useful completions.

So yeah, I'd also consider this a duplicate.