Separate file utilities from utils.cc

Reduce the dependencies from utils.cc to arch/ subdirectories, etc.

Bug: 22322814
Test: make test-art-host
Change-Id: I4decd15ff4ec460735bfb58cebb1c6a1bf32b68f
diff --git a/runtime/gc/verification.cc b/runtime/gc/verification.cc
index beb43df..3cd04a6 100644
--- a/runtime/gc/verification.cc
+++ b/runtime/gc/verification.cc
@@ -20,6 +20,7 @@
 #include <sstream>
 
 #include "art_field-inl.h"
+#include "base/file_utils.h"
 #include "mirror/class-inl.h"
 #include "mirror/object-refvisitor-inl.h"