warning on bad chdir

matches zend

hphp/runtime/ext/ext_file.cpp

@@ -1277,6 +1277,7 @@ bool f_chdir(CStrRef directory) {
     g_context->setCwd(File::TranslatePath(directory));
     return true;
   }
+  raise_warning("No such file or directory (errno 2)");
   return false;
 }
 

hphp/test/quick/chdir.php

@@ -0,0 +1,3 @@
+<?php
+
+var_dump(chdir('/this_should_not_exist'));

hphp/test/quick/chdir.php.expectf

@@ -0,0 +1,2 @@
+HipHop Warning: No such file or directory (errno 2) in %s/test/quick/chdir.php on line 3
+bool(false)