[MLIR][BufferResultsToOutParamsPass] Add Option to Modify Public Function's Signature (#167248)
Since https://github.com/llvm/llvm-project/pull/162441,
`buffer-results-to-out-params` transforms `private` functions only.
But, as mentioned in
https://github.com/llvm/llvm-project/pull/162441#issuecomment-3404195242,
this is a breaking change for pipelines handling C code. Our pipeline
@EfficientComputer is also affected by this breaking change.
Therefore, this PR adds an opt-in flag to allow `public` functions to be
transformed by `BufferResultsToOutParamsPass`.