Bug in obfuscate js code.

まだ誰も着手していません。

First at all, sorry for my english, i will try to explain it as better as possible.

I have the following js code:

```javascript
export const Painter = function (elements, data) {
let title = elements.title;
let container = elements.container;
this.prePaint = () => { };
this.paint = () => { };
this.postPaint = () => { };
let finalPaint = () => {
this.prePaint = () => { };
this.paint = () => { };
this.postPaint = () => { };
createPromise();
};

let createPromise = () => {
return new Promise((resolve, reject) => {
this.paint = () => { resolve() }
}).then(() => {
this.prePaint(elements, data);
title.innerHTML = data.title;
container.innerHTML = data.html;
this.postPaint(elements, data);
finalPaint();
});
}

createPromise();
};
```

When i obfuscate this code, it seems like this (it was minimized and formatted by the browser):
```javascript
5: [function(a, b, c) {
"use strict";
Object[_0x56ae("0x6")](c, _0x56ae("0x6e"), {
value: !0
});
c[_0x56ae("0xb5")] = function(a, b) {
var c = this
, d = a[_0x56ae("0xb6")]
, e = a[_0x56ae("0xb7")];
this.prePaint = function() {} //// THIS LINE
,
this[_0x56ae("0xb8")] = function() {}
,
this[_0x56ae("0xb9")] = function() {}
;
var f = function() {
c[_0x56ae("0xba")] = function() {}
,
c.paint = function() {} ///// THIS LINE TOO
,
c.postPaint = function() {} ///// AND THIS LINE TOO
,
g()
}
, g = function() {
return new Promise(function(a) {
c.paint = function() {
a()
}
}
)[_0x56ae("0x24")](function() {
c[_0x56ae("0xba")](a, b),
d.innerHTML = b[_0x56ae("0xb6")],
e.innerHTML = b[_0x56ae("0x34")],
c.postPaint(a, b),
f()
})
};
g()
}
}
, {}]
```

You can see, how the fisrt this.prePaint has not transformed to this[_0x56ae("0xba")] and when this is called, it said undefined function.
But if i insert breaklines between all this "problematic" lines, it work. Like this:

```javascript

export const Painter = function (elements, data) {
let title = elements.title;
let container = elements.container;

this.prePaint = () => { };

this.paint = () => { };

this.postPaint = () => { };

let finalPaint = () => {

this.prePaint = () => { };

this.paint = () => { };

this.postPaint = () => { };

createPromise();
};

let createPromise = () => {
return new Promise((resolve, reject) => {

this.paint = () => { resolve() }

}).then(() => {
this.prePaint(elements, data);

title.innerHTML = data.title;
container.innerHTML = data.html;

this.postPaint(elements, data);

finalPaint();

});
}

createPromise();
};
```

I did fix this issue with this partial solution, but i don't know where more places of my code, will appear the same issue.

Thank you

リポジトリのファイル、テスト、バージョン、設定のいずれも指定されていません。まず、提供された Painter の例を gulp の難読化パイプラインで再現し、this.prePaint、this.paint、this.postPaint に対して生成された参照を比較します。難読化されたコードが、改行の挿入を必要とせずに呼び出し可能なプロパティ参照を保持していれば完了です。

索引モデルが issue の本文から書いたものです。