Rollup merge of #86843 - FabianWolff:issue-86820, r=lcnr

Rollup merge of #86843 - FabianWolff:issue-86820, r=lcnr

Check that const parameters of trait methods have compatible types

This PR fixes #86820. The problem is that this currently passes the type checker:
```rust
trait Tr {
    fn foo<const N: u8>(self) -> u8;
}

impl Tr for f32 {
    fn foo<const N: bool>(self) -> u8 { 42 }
}
```
i.e. the type checker fails to check whether const parameters in `impl` methods have the same type as the corresponding declaration in the trait. With my changes, I get, for the above code:
```
error[E0053]: method `foo` has an incompatible const parameter type for trait
 --> test.rs:6:18
  |
6 |     fn foo<const N: bool>(self) -> u8 { 42 }
  |                  ^
  |
note: the const parameter `N` has type `bool`, but the declaration in trait `Tr::foo` has type `u8`
 --> test.rs:2:18
  |
2 |     fn foo<const N: u8>(self) -> u8;
  |                  ^

error: aborting due to previous error
```
This fixes #86820, where an ICE happens later on because the trait method is declared with a const parameter of type `u8`, but the `impl` uses one of type `usize`:
> `expected int of size 8, but got size 1`