var concreteCases []oneCase
	var interfaceCases []oneCase
	flush := func() {
		// Process all the concrete types first. Because we handle shadowing
		// below, it is correct to do all the concrete types before all of
		// the interface types.
		// The concrete cases can all be handled without a runtime call.
		if len(concreteCases) > 0 {
			var clauses []typeClause