The root issue for all TODOs

[sergeypospelov]

This issue contains all TODOs, so as not to forget them. If you complete any todo from this list, don't forget to add a link to the report in some form.

TODOs

• Benchmark different ways of collecting a guard in the HeapRefSplittingUtil::filter.
• Make a single ite not only for symbolic heap refs, but for concrete heap refs too.
• Compare eager and lazy UModel performance.
• Structure source files into packages. Fixed in Restructure packages #13
• Add simplifying UFlatUpdates in UComposer (case composing on UModel, where stores are concretized and we expect a concrete reading returns a concrete value). Added in Introduce UExprTranslator, UModelBase and revise regions composition #9
• mkDistinct with concrete heap refs.
• Interning URegionIds.
• Choose constant names carefully in UExprTranslator.
• Deal with big arrays in composition. Idea: we can create a ranged update node with copy from big array and apply it to heap.
• Localized map in memory regions compostion.
• Refactor UHeap to generic implementation with getMemoryRegion(regionId: URegionId).
• Fix Type/ArrayType inconsistence.
• Make recursive-free implementations in UFlatUpdates.
• Implement UMemory::memset. Added in Malloc with initializer & memset #17
• Revision and design UComponents and DI in usvm.
• Implement approximations for Throwable.
• Choose a better way to place close function, related to this PR.
• Refactor namings in RegionTree and all usages. Fixed in Region tree renaming and fix #26
• Fix equals for update nodes and add related tests.
• Think again about array casts and type elations with their elements.
• Think about region refinement with bv constraints and their interaction with memory regions (eager vs lazy style). includesConcretely, includesSymbolically look like good extension points.
• Fix translator cache usage in lazy models. Fixed in Fix and refactor decoder and translator #28
• Make cache in DfsIterator optional
• Refactor the splitting read mechanism.