optimizing: Refactor statistics to use OptimizingCompilerStats helper

Remove all copies of 'MaybeRecordStat', replacing them with a single
OptimizingCompilerStats::MaybeRecordStat helper.

Change-Id: I83b96b41439dccece3eee2e159b18c95336ea933
diff --git a/compiler/optimizing/load_store_elimination.h b/compiler/optimizing/load_store_elimination.h
index efe71c7..20a8a76 100644
--- a/compiler/optimizing/load_store_elimination.h
+++ b/compiler/optimizing/load_store_elimination.h
@@ -28,8 +28,9 @@
  public:
   LoadStoreElimination(HGraph* graph,
                        const SideEffectsAnalysis& side_effects,
-                       const LoadStoreAnalysis& lsa)
-      : HOptimization(graph, kLoadStoreEliminationPassName),
+                       const LoadStoreAnalysis& lsa,
+                       OptimizingCompilerStats* stats)
+      : HOptimization(graph, kLoadStoreEliminationPassName, stats),
         side_effects_(side_effects),
         lsa_(lsa) {}