prefer typed/strict operations;

--- a/src/Pure/PIDE/headless.scala	Fri Jan 27 16:18:36 2023 +0100
+++ b/src/Pure/PIDE/headless.scala	Fri Jan 27 16:48:19 2023 +0100
@@ -90,7 +90,7 @@
       def finished: Load_State = Load_State(Nil, Nil, 0)
 
       def count_file(name: Document.Node.Name): Long =
-        if (loaded_theory(name)) 0 else name.path.file.length
+        if (loaded_theory(name)) 0 else File.space(name.path).bytes
     }
 
     private case class Load_State(