This change simplifies BufferizableOpInterface and other functions. Overall, the API will get smaller: Functions related to custom IR traversal are deleted entirely. This will makes it easier to write BufferizableOpInterface implementations.
This is also in preparation of unifying Comprehensive Bufferize and core bufferization. While Comprehensive Bufferize could theoretically maintain its own IR traversal, there is no reason to do so, because all bufferize implementations in BufferizableOpInterface have to support partial bufferization anyway. And we can share a larger part of the code base between the two bufferizations.
Differential Revision: https://reviews.llvm.org/D116448
15c7e3ee15