relates to:

• SR-4691 SE-0155 Normalize Enum Case Representation

Issue Description:

In the code below we partially match the .foo enum case as case .foo(bar: let x):, clearly the second associated value is missing but it still compiles.

public enum A {
    case foo(bar: String, buz: Int)
}

func f(_ a: A) {
    switch a {
        case .foo(bar: let x):
            print(x)
    }
}

f(.foo(bar: "hello world", buz: 42))

It just totally ignores the "bar:" bit and makes x be the tuple ("hello world", 42).