Leak in reflect when using Load() against JSON file (on a non-Register()ed type)

[igorastds]

TL;DR:
bug.json:
{"Head": {"StepSize": 2,"Hacks": {"Backup": {"A": 1,"Users": [1, 2, 3, 4],"S":"S"}}}}

	cfg.Load("bug.json")
        foo struct { Hacks struct { Backup struct { Users []int } } }
x:
	cfg.Configure(&foo, "Head")
	if len(foo.Hacks.Backup.Users) < 1 {
		tries++
		goto x
	}
	log.Println(fmt.Sprintf("ok done, took %d tries, got %v", tries, foo.Hacks.Backup.Users))

The results to get this structure parsed are varying between taking 8000 - 160000 tries on my machine, and this is not even supposed to work I guess. Test code: http://pastebin.com/FLQVtDYZ, tested on 1.6.2 and 1.8

[qiangxue]

Issue confirmed. I will look into it. Thanks!