Use non volatile lock words in semispace collector.

GSS FormulaEvaluationActions.EvaluateAndApplyChanges:
Before GC time: 9.1s
After GC time: 7.98s

Fixed timing logger errors.

Change-Id: I4193c6ccbbbe7a7220dfaabbf3472a5dcebae616
diff --git a/runtime/gc/collector/semi_space.h b/runtime/gc/collector/semi_space.h
index 4169ca9..b6726b2 100644
--- a/runtime/gc/collector/semi_space.h
+++ b/runtime/gc/collector/semi_space.h
@@ -231,6 +231,11 @@
   // whole_heap_collection_ once per interval.
   int whole_heap_collection_interval_counter_;
 
+  // How many objects and bytes we moved, used so that we don't need to get the size of the
+  // to_space_ when calculating how many objects and bytes we freed.
+  size_t bytes_moved_;
+  size_t objects_moved_;
+
   // How many bytes we avoided dirtying.
   size_t saved_bytes_;