Alignment constraints on `Storable`/`alloca`
- It's unclear if the alignment value of a Storeable instance must be a power of two. (Probably should)
- Currently alloca does not mention any alignment requirements or guarantess, but ends up allocating aligned memory. (Which is reasonable).
Ideas:
- Add preconditions to alloca in regards to the storable instance it ends up using.
- Or alloca could round up to the nearest power of two.
- In regards to Storeable we probably just want to add a requirement on the alignment to be a power of two.