WIP: feat: integrate simp_mem with sym_n

[alexkeizer]

Description:

This PR is stacked on #222.

This PR starts the integration, by adding a call to simp_mem to the effect aggregation post-processing step of sym_n.

Testing:

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

Yes, make all succeeds.

License:

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

NOTE: this PR is owned by @bollu, I (alex) merely opened it because we started pairing on my machine

[alexkeizer]

@bollu

[bollu]

@alexkeizer comment addressed!

[bollu]

@alexkeizer is this an LGTM from you?

[shigoel]

@alexkeizer @bollu Converting to draft until comments are resolved.

[alexkeizer]

@bollu I separated out the MemoryEffects structure refactor into its own PR, without the simp_mem call at the end of sym_n (which is still in the current PR), because I don't think the latter is quite ready to be merged yet.