function isModifyingReference(reference, index, references) {
	const identifier = reference.identifier;

	/*
	 * Destructuring assignments can have multiple default value, so
	 * possibly there are multiple writeable references for the same
	 * identifier.
	 */
	const modifyingDifferentIdentifier =
		index === 0 || references[index - 1].identifier !== identifier;

	return (
		identifier &&
		reference.init === false &&
		reference.isWrite() &&
		modifyingDifferentIdentifier
	);
}
Checks reference if is non initializer and writable.
@param {Reference} reference A reference to check.
@param {number} index The index of the reference in the references.
@param {Reference[]} references The array that the reference belongs to.
@returns {boolean} Success/Failure
@private