golang issue7538a 代码
文件路径：/test/fixedbugs/issue7538a.go
/ errorcheck
/ Copyright 2014 The Go Authors. All rights reserved.
/ Use of this source code is governed by a BSD-style
/ license that can be found in the LICENSE file.
/ Issue 7538: blank (_) labels handled incorrectly
package p
func f() {
_:
_:
goto _ / ERROR "not defined|undefined label"
}