parseArgs in runtimes where global is not defined #157

This module is useful as a polyfill for older Node versions. But it could also be useful for other runtimes, such as gjs, that may not want to implement a Node compatibility layer but nevertheless would find a good argument parser helpful.

Right now this module appears to polyfill a bunch of Node internal functions by modifying global (such as in internal/primordials.js). This is fine, even preferrable, when it was to be included in Node, but as a standalone library this has two problems:

1. This pollutes the global namespace, which is inappropriate in non-Node contexts. A hypothetical case is someone wanting to emulate command parsing in the browser and utilizing this library - which works, but their namespace is now polluted.

2. This doesn't work in some runtimes. Some runtimes do not have global (generally they have globalThis though), so the modification of global means this library just doesn't work there, even though it could.

   My actual use case is that I'm making a command line program with gjs (to make use of GLib). parseArgs({args: ARGV, options: {...}}) would work wonders there, but the polyfilling behavior prevents it from working. (ARGV is gjs's equivelant to process.argv.slice(2))

   Runtimes that have some use and don't have global:

   • gjs: has globalThis instead
   • duktape (online REPL): has globalThis instead
   • QuickJS (online REPL based on QuickJS): has globalThis instead

This can be fixed by either:

• Moving away from being a polyfill (which, granted, is quite a big change to make), or
• Falling back to globalThis if global doesn't exist.