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/debug/method_debug_info.h b/compiler/debug/method_debug_info.h
index a8225fa..43c8de2 100644
--- a/compiler/debug/method_debug_info.h
+++ b/compiler/debug/method_debug_info.h
@@ -21,7 +21,7 @@
 
 #include "arch/instruction_set.h"
 #include "base/array_ref.h"
-#include "dex_file.h"
+#include "dex/dex_file.h"
 
 namespace art {
 namespace debug {