Make BCE a no-op if there is no array access.

Change-Id: I8456182808c1dbaa0c0ae1b8c2e94bb17baf5f29
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 98076a0..b7dd756 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -113,6 +113,7 @@
         number_of_vregs_(0),
         number_of_in_vregs_(0),
         temporaries_vreg_slots_(0),
+        has_array_accesses_(false),
         current_instruction_id_(start_instruction_id) {}
 
   ArenaAllocator* GetArena() const { return arena_; }
@@ -199,6 +200,14 @@
     return reverse_post_order_;
   }
 
+  bool HasArrayAccesses() const {
+    return has_array_accesses_;
+  }
+
+  void SetHasArrayAccesses(bool value) {
+    has_array_accesses_ = value;
+  }
+
   HNullConstant* GetNullConstant();
 
  private:
@@ -236,6 +245,9 @@
   // Number of vreg size slots that the temporaries use (used in baseline compiler).
   size_t temporaries_vreg_slots_;
 
+  // Has array accesses. We can totally skip BCE if it's false.
+  bool has_array_accesses_;
+
   // The current id to assign to a newly added instruction. See HInstruction.id_.
   int32_t current_instruction_id_;