const internal/types/errors.UnusedVar

4 uses

	internal/types/errors (current package)
		code_string.go#L109: 	_ = x[UnusedVar-101]
		codes.go#L940: 	UnusedVar

	go/types
		stmt.go#L72: 		check.softErrorf(v, UnusedVar, "declared and not used: %s", v.name)
		stmt.go#L782: 				check.softErrorf(lhs, UnusedVar, "%s declared and not used", lhs.Name)