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/common_runtime_test.cc b/runtime/common_runtime_test.cc
index 149c33f..f15acf9 100644
--- a/runtime/common_runtime_test.cc
+++ b/runtime/common_runtime_test.cc
@@ -27,6 +27,7 @@
 #include "android-base/stringprintf.h"
 
 #include "art_field-inl.h"
+#include "base/file_utils.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/stl_util.h"