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/cmdline/cmdline.h b/cmdline/cmdline.h
index c5d3a6b..2929f36 100644
--- a/cmdline/cmdline.h
+++ b/cmdline/cmdline.h
@@ -26,6 +26,7 @@
 
 #include "android-base/stringprintf.h"
 
+#include "base/file_utils.h"
 #include "base/logging.h"
 #include "base/stringpiece.h"
 #include "noop_compiler_callbacks.h"