...of the type being matched.
This change will result in a better diagnostic for code like the following:
```rust
enum Enum {
Foo,
Bar
}
fn f(x: Enum) {
match x {
Foo => (),
Bar => ()
}
}
```
which would currently simply fail with an unreachable pattern error
on the 2nd arm.
The user is advised to either use a qualified path in the patterns
or import the variants explicitly into the scope.