Support garbage collection of JITted code.

Change-Id: I9afc544460ae4fb31149644b6196ac7f5182c784
diff --git a/runtime/art_method.h b/runtime/art_method.h
index 9f1495c..bb9804e 100644
--- a/runtime/art_method.h
+++ b/runtime/art_method.h
@@ -433,6 +433,10 @@
     return ++hotness_count_;
   }
 
+  void ClearCounter() {
+    hotness_count_ = 0;
+  }
+
   const uint8_t* GetQuickenedInfo() SHARED_REQUIRES(Locks::mutator_lock_);
 
   // Returns the method header for the compiled code containing 'pc'. Note that runtime