[absint] do not fail when not finding a pre

Summary: This code sometimes fails when there are unreachable nodes in the CFG. This diff should stop the failures while we investigate why this happens.

Reviewed By: davidpichardie

Differential Revision: D63024067

fbshipit-source-id: 58ba81d2f4c9f67956b4382771a641b66509859c

infer/src/absint/AbstractInterpreter.ml

@@ -815,7 +815,9 @@ module MakeWTONode (TransferFunctions : NodeTransferFunctions) = struct
     | Some astate_pre ->
         exec_node ~pp_instr proc_data node ~is_loop_head ~is_narrowing astate_pre inv_map
     | None ->
-        L.(die InternalError) "Could not compute the pre of a node"
+        L.internal_error "Could not compute the pre of a node in %a\@n" Procname.pp
+          (Procdesc.Node.get_proc_name (Node.underlying_node node)) ;
+        (inv_map, DidNotReachFixPoint)
 
 
   (* [WidenThenNarrow] mode is to narrow the outermost loops eagerly, so that over-approximated