Compiler could give better suggestions on generics type.

Code

pub struct Point<T> {
    x: T,
}
pub trait MyTrait1 {
    fn fun(&self, p: Point<T>);
}
pub struct MyStruct;
impl MyTrait1 for MyStruct {
    fn fun(&self, p: Point<T>) {
        todo!();
    }
}
fn main() {
    todo!();
}

Current output

error[E0412]: cannot find type `T` in this scope
 --> src/main.rs:5:28
  |
5 |     fn fun(&self, p: Point<T>);
  |                            ^ not found in this scope

error[E0412]: cannot find type `T` in this scope
 --> src/main.rs:9:28
  |
9 |     fn fun(&self, p: Point<T>) {
  |                            ^ not found in this scope
  |
help: you might be missing a type parameter
  |
8 | impl<T> MyTrait1 for MyStruct {
  |     +++

For more information about this error, try `rustc --explain E0412`.
error: could not compile `playground` (bin "playground") due to 2 previous errors

Desired output

error[E0412]: cannot find type `T` in this scope
 --> src/main.rs:5:28
  |
5 |     fn fun(&self, p: Point<T>);
  |                            ^ not found in this scope

error[E0412]: cannot find type `T` in this scope
 --> src/main.rs:9:28
  |
9 |     fn fun(&self, p: Point<T>) {
  |                            ^ not found in this scope
  |
help: you might be missing a type parameter
  |
9 | fn fun<T>(&self, p: Point<T>) {
  |       +++

For more information about this error, try `rustc --explain E0412`.
error: could not compile `playground` (bin "playground") due to 2 previous errors

Rationale and extra context

The suggestions for adding type parameters should be specific to the function itself rather than the entire implementation.

Other cases

No response

Anything else?

No response

Reproduce the provided Rust snippet and inspect the rustc E0412 diagnostic and its suggestion output. No repository file or test is named in the issue, so locate the diagnostic handling for this case before adding coverage. Done means the suggestion targets fn fun with the type parameter, rather than the impl block.