[llvm] [RFC] implement convergence control in MIR using SelectionDAG (PR #71785)

[Sameer Sahasrabuddhe via llvm-commits]

ssahasra wrote:

#67006 is a slightly outdated attempt at doing the same thing with GlobalISel. That other PR will be redesigned after completing this current PR.

https://github.com/llvm/llvm-project/pull/71785