[feature request] implement optional chaining as now has full support

[DerekNonGeneric]

Seems like we should be using optional chaining syntax (?.) in the loader source code now that it is stage 4 and well-supported. At the time when this was written, that language feature was relatively new and not yet generally available.

See:

loader339/sample/load-sample.mjs

Lines 56 to 61 in 8260406

	if (typeof original === 'function') {
	module.exports.default = function() {
	return original.apply(this, arguments);
	};
	} else {
	module.exports.default = original;

[DerekNonGeneric]

Relevant: https://twitter.com/LeaVerou/status/1672315249238614041