Update to IRMutator2, expr_match is overkill.
Update to IRMutator2, expr_match is overkill.


Former-commit-id: a20fdc16e82c67346e7e5b6ad400e98a6f1d7bff [formerly 46607bcb156cb4f4917d2ca9a070b71ae643d3e0]
Former-commit-id: 565a53893bee5c2587668eeb1a176d541655edce
Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,darkbuck/Halide,darkbuck/Halide,Trass3r/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide,darkbuck/Halide,Trass3r/Halide