9a767dce95
Adds an option to allow modification of public functions to the drop equivalent buffer results API and the respective pass. A new standalone test for the pass is also added. https://github.com/llvm/llvm-project/pull/163001 modified the default behavior by disallowing rewriting public function. This PR preserves the new behavior and only adds an opt-in flag to reenable changing public function. The extra flag aligns dropping equivalent function results with another bufferization API `promoteBufferResultsToOutParams` which also allows opt-in public function rewriting.