Create TestReducer pass

- Create a pass that generates bugs based on trivially defined behavior for the purpose of testing the MLIR Reduce Tool.
- Implement the functionality inside the pass to crash mlir-opt in the presence of an operation with the name "crashOp".
- Register the pass as a test pass in the mlir-opt tool.

Reviewed by: jpienaar

Differential Revision: https://reviews.llvm.org/D83422