JSON parser fails to parse JSON generated from HCL

The following code fails:

``` go
package main

import (
"encoding/json"
"reflect"

"github.com/hashicorp/hcl"
)

var hclData = []byte(`match "first" {
type = "test"
value = "first"
}
match "second" {
type = "test"
value = "second"
match "inner" {
type = "test"
value = "third"
}
}
`)

type Data struct {
Matches []*Match `json:"match" hcl:"match"`
}
type Match struct {
Type string `json:"type" hcl:"type"`
Value string `json:"value" hcl:"value"`
Matches []*Match `json:"match,omitempty" hcl:"match"`
}

func main() {
var d, e *Data
err := hcl.Unmarshal(hclData, &d)
if err != nil {
panic("failed to unmarshal hclData: " + err.Error())
}
jData, err := json.MarshalIndent(d, "", " ")
if err != nil {
panic("failed to marshal into jData: " + err.Error())
}

err = hcl.Decode(&e, string(jData))
if err != nil {
panic("failed to parse jData: " + err.Error())
}
if !reflect.DeepEqual(d, e) {
jd, _ := json.Marshal(d)
je, _ := json.Marshal(e)
panic("parsed data differs: \n" + string(jd) + "\n" + string(je) + "\n")
}
}
```

Start by running the provided main program and trace hcl.Unmarshal and hcl.Decode with the nested match data. Compare the JSON produced by json.MarshalIndent with the decoded structure; done means decoding that JSON succeeds and preserves the original nested Data value.

Written by the indexing model from the issue text.