I've just updated to LE 7.90.001 8.0 with a clean install on my Rpi3. I've used LibreELEC-RPi2.arm-7.90.001.img and wrote it to the SD using dd.
Afterwards I've added dtoverlay=lirc-rpi to /flash/config.txt while the SD was still in the cardreader.
Then I've booted LE the first time with the Rpi and the remote was working. But after the first reboot the remote stopped working.
The issue was caused because the whole overlays folder in /flash was missing after the first reboot. After remounting /flash and put it back the remote works again.