very weird warning when using same varname for const and let binding

[matthiaskrgr]

Code

pub fn main() {
    const y: i32 = 4;
    let y: i32 = 3;
}

This will cause rustc to interpret the y as a if let binding for some reason which seems quite surprising.

error[E0005]: refutable pattern in local binding
 --> src/main.rs:3:9
  |
3 |     let y: i32 = 3;
  |         ^ patterns `i32::MIN..=3_i32` and `5_i32..=i32::MAX` not covered
  |
  = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
  = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html
  = note: the matched value is of type `i32`
help: you might want to use `if let` to ignore the variants that aren't matched
  |
3 |     if let y: i32 = 3 { todo!() };
  |     ++                +++++++++++

For more information about this error, try `rustc --explain E0005`.

When I replace let by static, I get a warning that seems to be much closer to reality:

pub fn main() {
    const y: i32 = 4;
    static y: i32 = 3;
}

error[E0428]: the name `y` is defined multiple times
 --> src/main.rs:3:5
  |
2 |     const y: i32 = 4;
  |     ----------------- previous definition of the value `y` here
3 |     static y: i32 = 3;
  |     ^^^^^^^^^^^^^^^^^^ `y` redefined here
  |
  = note: `y` must be defined only once in the value namespace of this block

For more information about this error, try `rustc --explain E0428`.
error: could not compile `playground` (bin "playground") due to previous error

IMO it would make sense to issue such warning for the first case as well, instead of the if-let/range diagnostic.