[Diagnostics] Fix diagnostic improved after labeling changes

Author: xedin

test/Constraints/patterns.swift

@@ -291,7 +291,9 @@ switch staticMembers {
   case .init(0): break
   case .init(_): break // expected-error{{'_' can only appear in a pattern}}
   case .init(let x): break // expected-error{{cannot appear in an expression}}
-  case .init(opt: 0): break // expected-error{{pattern cannot match values of type 'StaticMembers'}}
+  case .init(opt: 0): break // expected-error{{value of optional type 'StaticMembers?' must be unwrapped to a value of type 'StaticMembers'}}
+  // expected-note@-1 {{force-unwrap using '!' to abort execution if the optional value contains 'nil'}}
+  // expected-note@-2 {{coalesce using '??' to provide a default when the optional value contains 'nil'}}
 
   case .prop: break
   // TODO: repeated error message