Transfer functions that push abstract states across instructions. A typical client should implement the Make signature to allow the transfer functions to be used with any kind of CFG.

`module type S : sig ... end`
`module type SIL : sig ... end`
`module type HIL : sig ... end`
`module type MakeSIL : functor (C : InferModules.ProcCfg.S) -> sig ... end`
`module type MakeHIL : functor (C : InferModules.ProcCfg.S) -> sig ... end`