Measure when MLIR is faster or slower to update the heuristic

[pfultz2]

Gather mxr/pythons files from all the models including for NCHW/NHWC/fp16/bf16/fp32 and rewrite_dot/on/off. Measure the performance for each file with and without MLIR on all the different hardware. Make a list for when MLIR is slower and use that list to update the heuristic for when we pick MLIR.