Enable cat wo conditionals iff cpu (#58026)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/58026
Cat-without-conditionals is a valuable optimization on CPU but on GPU
it can generate invalid code since it may introduce allocations (i.e. extra
kernel launches)
ghstack-source-id: 128748630
Test Plan: predictor
Reviewed By: navahgar
Differential Revision: D28347703
fbshipit-source-id: f9e68cd7bcf5d316082ce8378ddf99f2d33fcc07
