[hackc] add hhbc_iter_base model and update hackc version

Summary:
a recent change in hackc broke our unit tests, by introducing a new builtin.
We fix the problem by adding a trivial model.

Reviewed By: jvillard

Differential Revision: D55745317

fbshipit-source-id: fb788ea000fe684c1b1f03ffe8a0217ba81d77d9

infer/src/pulse/PulseModelsHack.ml

@@ -1168,6 +1168,11 @@ let hhbc_add x y : model =
  assign_ret sum (* unconstrained value *)
 
 
+let hhbc_iter_base arg : model =
+ let open DSL.Syntax in
+ start_model @@ assign_ret arg
+
+
 let hhbc_iter_init iteraddr keyaddr eltaddr arg : model =
  let open DSL.Syntax in
  start_model
@@ -1422,6 +1427,7 @@ let matchers : matcher list =
  $--> Vec.vec_from_async
  ; -"$root" &:: "FlibSL::Dict::from_async" <>$ capt_arg_payload $+ capt_arg_payload
  $--> Dict.dict_from_async
+ ; -"$builtins" &:: "hhbc_iter_base" <>$ capt_arg_payload $--> hhbc_iter_base
  ; -"$builtins" &:: "hhbc_iter_init" <>$ capt_arg_payload $+ capt_arg_payload $+ capt_arg_payload
  $+ capt_arg_payload $--> hhbc_iter_init
  ; -"$builtins" &:: "hhbc_iter_next" <>$ capt_arg_payload $+ capt_arg_payload $+ capt_arg_payload