[llvm] [DAGCombine] Propagate truncate to operands (PR #98666)

[Justin Fargnoli via llvm-commits]

justinfargnoli wrote:

Ping @topperc @RKSimon @arsenm for review. 

If I don't hear back by Thursday, 10/3/24, I plan to opt for a post-commit review. 

https://github.com/llvm/llvm-project/pull/98666