function replaceSimpleFunctionCall(code, replacer) {
	return code.replace(/(?<![.\w])([a-z$_][\w$]*)\((['"`])((?:(?!\2)[^\\]|\\.)*?)\2\)/gi, (s, fn, quote, url) => {
		const ret = replacer(fn, url, quote);
		return ret == null ? s : ret;
	});
}
Replace function calls of the form `$fn("$url")` with a value returned by a function.
This is brittle. It should only be used for generated code and must account for it having been minified.
@param {string} code
@param {(fn: string, url: string, quote: string) => string | null | undefined} replacer Return replacement code, or `null`/`undefined` to preserve the matched call.