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/common_throws.cc b/runtime/common_throws.cc
index 8de3068..970593d 100644
--- a/runtime/common_throws.cc
+++ b/runtime/common_throws.cc
@@ -16,6 +16,8 @@
 
 #include "common_throws.h"
 
+#include <sstream>
+
 #include "base/logging.h"
 #include "class_linker-inl.h"
 #include "dex_file-inl.h"
@@ -25,12 +27,9 @@
 #include "mirror/class-inl.h"
 #include "mirror/object-inl.h"
 #include "mirror/object_array-inl.h"
-#include "object_utils.h"
 #include "thread.h"
 #include "verifier/method_verifier.h"
 
-#include <sstream>
-
 namespace art {
 
 static void AddReferrerLocation(std::ostream& os, mirror::Class* referrer)