Log reverse analysis call graph statistics

Summary:
This adds logging of the number of nodes in the reverse analysis call graph, and the number of these nodes that are invalidated by incremental analysis.

This data will show the precision of incremental analysis.

Reviewed By: ngorogiannis

Differential Revision: D16939101

fbshipit-source-id: 1e465f1a6

infer/src/backend/InferAnalyze.ml

@@ -161,6 +161,8 @@ let invalidate_changed_procedures changed_files =
   L.progress
     "Incremental analysis: %d nodes in reverse analysis call graph, %d of which were invalidated @."
     total_nodes invalidated_nodes ;
+  ScubaLogging.log_count ~label:"incremental_analysis.total_nodes" ~value:total_nodes ;
+  ScubaLogging.log_count ~label:"incremental_analysis.invalidated_nodes" ~value:invalidated_nodes ;
   (* save some memory *)
   CallGraph.reset reverse_callgraph