See the releases page for prebuilt packages. USE AT YOUR OWN RISK.
This is the vanilla Arch package with a patch that prevents the iwlwifi driver from becoming unusable due to a beacon timeout firmware issue.
To use this, use the following kernel module parameter (e.g., in /etc/modprobe.d/wifi-fix.conf):
options iwlwifi beacon_timeout=256
The number 256 is the number of beacons that must be missed before the driver disconnects.