[feature request] Convert functions to arrow functions

I think Babili could save a lot of bytes with a plugin that converts functions that do not make use of this to arrow functions:

Input (34):

function foo() {
  return 'bar';
}

Output(18):

let foo=()=>'bar';
// or 20 with `const`

Current result: https://babeljs.io/repl/#?babili=true&evaluate=true&lineWrap=false&presets=es2015%2Creact%2Cstage-2&code=function foo() { return ‘bar’%3B }

[Andarist]

Actually I think it could be determined (to some extent) if new is gonna be used. If resulting foo is local, not exported, not assigned to any object or reassigned it would be safe to apply such transformation. Wouldnt it?

[Pyrolistical]

yeah, but unsafe flags means most people would never use this feature and its not worth developing.

i would rather program a better static analyzer where if you can prove the closure is never newed then do the transform. it would be pretty tricky and you would need to add ability to recognize and follow promises.