[llvm] [CodeGen] Allow larger number of operands to be compiled by SelectionDAG (PR #122737)

[Simon Pilgrim via llvm-commits]

https://github.com/RKSimon commented:

What effect does this have on the class sizes? MCInstrDesc etc. look like you're going to end up with a lot more padding?

https://github.com/llvm/llvm-project/pull/122737