Catastrophic sounds strong. As far as `restrict` goes, C was never that far behind Fortran in performance.

And if maintaining `restrict` for other passes is really important, maybe the order of the passes should be changed. I'm not pretending compiler optimization is simple, but I can't see any situation where having an incorrect optimization pass run first is the right thing to do. The broken pass needs to be fixed, and it shouldn't have emitted code with incorrect `restrict` on it.