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/thread.cc b/runtime/thread.cc
index b3d14f0..8691dec 100644
--- a/runtime/thread.cc
+++ b/runtime/thread.cc
@@ -876,7 +876,7 @@
     if (o == nullptr) {
       os << "an unknown object";
     } else {
-      if ((o->GetLockWord().GetState() == LockWord::kThinLocked) &&
+      if ((o->GetLockWord(false).GetState() == LockWord::kThinLocked) &&
           Locks::mutator_lock_->IsExclusiveHeld(Thread::Current())) {
         // Getting the identity hashcode here would result in lock inflation and suspension of the
         // current thread, which isn't safe if this is the only runnable thread.