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/handle_scope-inl.h b/runtime/handle_scope-inl.h
index 62c7614..7bc811d 100644
--- a/runtime/handle_scope-inl.h
+++ b/runtime/handle_scope-inl.h
@@ -17,7 +17,7 @@
 #ifndef ART_RUNTIME_HANDLE_SCOPE_INL_H_
 #define ART_RUNTIME_HANDLE_SCOPE_INL_H_
 
-#include "handle_scope-inl.h"
+#include "handle_scope.h"
 
 #include "handle.h"
 #include "thread.h"