[llvm] [SDAG] Fix CSE for ADDRSPACECAST nodes (PR #122912)

[Justin Fargnoli via llvm-commits]

https://github.com/justinfargnoli approved this pull request.

This LGTM, but please wait for @arsenm's review as I'm not very familiar with the `NodeID` infra. 

https://github.com/llvm/llvm-project/pull/122912