Summary:
This diff evaluates a cpp vector given as a parameter symbolically. Especially, it addresses it as an array, so the cost checker can use its symbolic length correctly.
**About handling `cpp.vector_elem` field:**
The field is a virtual field of vector object that points to the array of vector elements. It was introduced in Inferbo to model semantics of vector operations.
Since many semantics of Inferbo depends on type information, it had collected type information of vector elements, whenever `cpp.vector_elem` field was introduced, as a *side-effect*. A problem is that it has *side-effect*, which means it may introduce non-deterministic analysis results depending on the type information of the virtual field.
This diff changes it not to collect the type information on `cpp.vector_elem` as a side-effect. Instead, it tries to write the information to the abstract states (abstract location) when possible.
Reviewed By: ezgicicek
Differential Revision: D27674935
fbshipit-source-id: f3d52cae7