[JIT] Lazily initialize aliasDb in DCE (#56649)
Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/56649
Test Plan: Imported from OSS
Reviewed By: ZolotukhinM
Differential Revision: D27926043
Pulled By: desertfire
fbshipit-source-id: 6f6cca6a8d32ac26d780a41edba1e6e653050a1f
