[mlir][bufferize][NFC] Make func BufferizableOpInterface impl compatible with One-Shot Bufferize

Bufferization of the func dialect must go through `OneShotModuleBufferize`. With this change, the analysis interface methods of the BufferizableOpInterface of func dialect ops can be used together with the normal `OneShotBufferize`. (In the absence of analysis information, they will return conservative results.)

Differential Revision: https://reviews.llvm.org/D127299