Do not unconditionally do new() to fill embedded struct pointer

[dynaxis]

In the case of encoding/json, if I set Inner of Test struct before unmarshalling, it is kept after unmarshalled. But in the case of easyjson, the generated implementation unconditionally do new(Inner)
and assign to the Test.Inner.

If there is no particular reason for doing it unconditionally, it would be good if easyjson works
the same way as encoding/json.

Thanks.

package main

import (
	"encoding/json"
	"fmt"
)

type Test struct {
	Dummy int
	*Inner
}

type Inner struct {
	Boo int
}

const data = `
{
	"Dummy": 7,
	"Boo": 3
}
`

func main() {
	t := &Test{}
	i := &Inner{}
	//t.Inner = i

	json.Unmarshal([]byte(data), t)
	fmt.Printf("Check: %v, %v, %v\n", t.Inner == i, t.Inner.Boo, t.Dummy)
}

[dynaxis]

Let me elaborate more on it. In my case, I have a struct and some more fields outside it that should be added only to JSON. So I created an outer struct with the additional fields and the original struct embedded as a pointer. So when I unmarshall it, I set pointer to the original struct to the outer struct and expect the pointer kept in tact filling data from JSON into it.

As a workaround, I'm currently copying the unmarshalled inner-struct to the struct that is passed into unmarshall methods.