When we have a type mismatch with a cause.code that is an ObligationCauseCode::Pattern, skip suggesting fixes like adding .await or accessing a struct's .field if the pattern's root_ty differs from the expected ty. This occurs in situations like this:

struct S(());

fn main() {
    let array = [S(())];
    
    match array {
        [()] => {}
        _ => {}
    }
}

I think what's happening here is a layer of [_; N] is peeled off of both types and we end up seeing the mismatch between just S and (), but when we suggest a fixup, that applies to the expression with type root_ty.

Questions:

1. Should this check live here, above all of the suggestions, or should I push this down into every suggestion when we match ObligationCauseCode?
2. Any other ObligationCauseCodes to check here?
3. Am I overlooking an easier way to get to this same conclusion without pattern matching on ObligationCauseCode and comparing root_ty?

Fixes #91058