DSE and Sinking performance regression in LLVM 14

[tetsuo-cpp]

As discussed in #297 (comment), DSEPass and SinkingPass are taking much longer on certain examples with LLVM 14 (30+ minutes for a lift that took a ~2 min on LLVM 13). Since we're not entirely sure that we need them, I'm just commenting them out for the time being and creating this issue to document this information in case we start producing IR that would benefit from DSE or sinking and would like to reenable them.

This is the JSON that reproduces the slowdown: cat.json.txt
This is a screenshot showing some profiling information for a lift of the attached program: