Related to #43513, I would like to enable Graphite2 in Harbuzz (to support a Nastaliq font). Theoretically, all that is required is to add the --with-graphite2 flag when building Harfbuzz. I've gone through the steps of setting up my own development environment for the flutter engine, but I'm at a loss on how to integrate that switch into the build process. Is what I'm trying to do even possible?