Absint.Exe_envExecution environments are a means to get a function's type environment and integer widths and cache those
val get_proc_tenv : IR.Procname.t -> IR.Tenv.treturn the type environment associated with the procedure
val get_source_tenv : IBase.SourceFile.t -> IR.Tenv.t optionreturn the type environment associated with the source file
val get_integer_type_widths : IR.Procname.t -> IR.IntegerWidths.treturn the integer type widths associated with the procedure