load seq.ML and position.ML earlier;

--- a/src/Pure/General/ROOT.ML	Tue May 13 17:06:14 2008 +0200
+++ b/src/Pure/General/ROOT.ML	Wed May 14 11:05:07 2008 +0200
@@ -12,6 +12,8 @@
 use "scan.ML";
 use "source.ML";
 use "symbol.ML";
+use "seq.ML";
+use "position.ML";
 use "../ML/ml_lex.ML";
 use "../ML/ml_parse.ML";
 use "secure.ML";
@@ -23,10 +25,8 @@
 use "balanced_tree.ML";
 use "graph.ML";
 use "name_space.ML";
-use "seq.ML";
 use "susp.ML";
 use "path.ML";
-use "position.ML";
 use "url.ML";
 use "file.ML";
 use "buffer.ML";