WIP: Experimental method to aggregate state effects

[shigoel]

Description:

Experimental method, inspired by simp_arith, to aggregate state effects.

Testing:

What tests have been run? Did make all succeed for your changes? Was
conformance testing successful on an Aarch64 machine?

Yes

License:

By submitting this pull request, I confirm that my contribution is
made under the terms of the Apache 2.0 license.

[bollu]

I find the name a bit confusing, and I'm also not sure why these need to be looked up. Can't they directly be (BitVec 64)s that are reflected?

[bollu]

I experimented with this a bit, and here's what I found:

1. It seems like we can cleanup at least some of the impl by using stdlib constructs like foldl. I did this in this commit: 7947bbf
2. Switching to Std.HashMap means that we can't straight up talk about the hashmaps being defeq (because they need not be structurally equal, only extensionally equal). Defining extensional equality and trying to switch to it also does not work, because we seem to lose defeqs: 6127856. I'm not sure why we lose defeq, maybe @alexkeizer can chime in. Best guess: something in HashMap uses well-founded recursion, not structural recursion, which breaks defeq :(

[shigoel]

Closing PR; working on a different implementation.