Remove object_utils.h.

Break into object_lock, field_helper and method_helper.
Clean up header files following this.
Also tidy some of the Handle code in response to compiler errors when resolving
the changes in this CL.

Change-Id: I73e63015a0f02a754d0866bfaf58208aebcaa295
diff --git a/runtime/utils.cc b/runtime/utils.cc
index b56bdd0..8b1ad39 100644
--- a/runtime/utils.cc
+++ b/runtime/utils.cc
@@ -28,6 +28,7 @@
 #include "base/stl_util.h"
 #include "base/unix_file/fd_file.h"
 #include "dex_file-inl.h"
+#include "field_helper.h"
 #include "mirror/art_field-inl.h"
 #include "mirror/art_method-inl.h"
 #include "mirror/class-inl.h"
@@ -35,7 +36,6 @@
 #include "mirror/object-inl.h"
 #include "mirror/object_array-inl.h"
 #include "mirror/string.h"
-#include "object_utils.h"
 #include "os.h"
 #include "scoped_thread_state_change.h"
 #include "utf-inl.h"