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/compiler/driver/compiler_driver.cc b/compiler/driver/compiler_driver.cc
index 7014c3b..9e88c8d 100644
--- a/compiler/driver/compiler_driver.cc
+++ b/compiler/driver/compiler_driver.cc
@@ -35,7 +35,7 @@
 #include "dex/quick/dex_file_method_inliner.h"
 #include "driver/compiler_options.h"
 #include "jni_internal.h"
-#include "object_utils.h"
+#include "object_lock.h"
 #include "profiler.h"
 #include "runtime.h"
 #include "gc/accounting/card_table-inl.h"