[Attributor] Re-enable a run line in noalias.ll

Authored by jdoerfert on Sep 4 2020, 9:41 AM.


[Attributor] Re-enable a run line in noalias.ll

This was disabled as we were looking for a weird CGSCC problem. I
think/hope we fixed it as there were a lot of updates recently. I could
never reproduce this locally so I'll use the pre-commit phab builds to
confirm this suspicion and if they seem to be happy I'll assume this is

Reviewed By: sstefan1

Differential Revision: https://reviews.llvm.org/D87266