reflect.DeepEqual  error for empty slice and variadic

demo
```
package main

import (
	"reflect"
)

func test1(v ...string) {
	var names []string
	ret := reflect.DeepEqual(names, v)
	println(ret)
}

func test2(opt int, v ...string) {
	var names []string
	ret := reflect.DeepEqual(names, v)
	println(ret)
}

func main() {
	test1()
	test2(100)
}
```

`gopherjs run main.go`

output error
```
true
false
```