[WIP] trace classes identifier that inherits from RegExp

[jean-michelet]

Related to #42

Todo:

1. Add tests in estree-ast-utils.
2. Trace member properties:

class MyRegExp extends RegExp {}

const y = {
    d: MyRegExp
}

const { d } = y

new y.d('(a+){10}'); // should add warning
new d('(a+){10}'); // should add warning