Create tooling for finding near-optimal order of optimizations

[Janiczek]

Order of optimizations matters.

It should be possible to look at the list of optimizations in Stage.Optimize.optimizeExpr and either experimentally or in some more scientific way find a better permutation of them.

This will probably need a corpus of programs or an expression fuzzer to evaluate the different orders on.

The result of this issue should be something reproducible, runnable on different inputs and with different set of optimizations to choose from. (ie. if we add a new optimization pass, we should be able to run this to find a new optimal order.)

This Reddit comment in particular seems like a great place to read up on various ways to do this, should you want to.