AssignmentPattern: escodegen removes = and add undefined

[wizzardio]

Hi, guys. I'm working with some esprima/escodegen task and during work I found one issue. I'm adding some changes to my code via these tools and when I re-create my code (after changes), escodegen removes = and add undefined.

Sample: const { option1, options: data = {}, callback } = args;

Received: const { option1, options: data undefined {}, callback } = args;

As I understood, escodegen has some troubles with new ES features, is it possible to fix in in some way or ignore.

[sanex3339]

This should be fixed