Create dex subdirectory

Move all the DexFile related source to a common subdirectory dex/ of
runtime.

Bug: 71361973
Test: make -j 50 test-art-host
Change-Id: I59e984ed660b93e0776556308be3d653722f5223
diff --git a/compiler/utils/atomic_dex_ref_map-inl.h b/compiler/utils/atomic_dex_ref_map-inl.h
index 00db09a..203e484 100644
--- a/compiler/utils/atomic_dex_ref_map-inl.h
+++ b/compiler/utils/atomic_dex_ref_map-inl.h
@@ -21,8 +21,8 @@
 
 #include <type_traits>
 
-#include "dex_file-inl.h"
 #include "class_reference.h"
+#include "dex/dex_file-inl.h"
 #include "method_reference.h"
 #include "type_reference.h"