Lazily initialize alias db constant prop (#54640)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/54640
If we are running constant propagation on a graph that doesn't have any operators with constant inputs and any mutable inputs/outputs, we do not need to initialize an alias db. This is going to be used to speed up symbolic shape analysis.
Test Plan: Imported from OSS
Reviewed By: nikithamalgifb
Differential Revision: D27340863
Pulled By: eellison
fbshipit-source-id: 087b2a33b42c58fa5dae405d652b056d0f1d72e7
