Move some remaining dex utilities

There were several utilities related to building/walking/testing dex
files that were not in libdexfile.  This change consolidates these.

Bug: 22322814
Test: make -j 50 test-art-host
Change-Id: Id76e9179d03b8ec7d67f7e0f267121f54f0ec2e0
diff --git a/oatdump/oatdump.cc b/oatdump/oatdump.cc
index 10da2ea..433ed9a 100644
--- a/oatdump/oatdump.cc
+++ b/oatdump/oatdump.cc
@@ -48,6 +48,7 @@
 #include "dex/descriptors_names.h"
 #include "dex/dex_file-inl.h"
 #include "dex/dex_instruction-inl.h"
+#include "dex/string_reference.h"
 #include "disassembler.h"
 #include "gc/accounting/space_bitmap-inl.h"
 #include "gc/space/image_space.h"
@@ -73,7 +74,6 @@
 #include "scoped_thread_state_change-inl.h"
 #include "stack.h"
 #include "stack_map.h"
-#include "string_reference.h"
 #include "thread_list.h"
 #include "type_lookup_table.h"
 #include "vdex_file.h"