flip logic so we only check for file existance if it looks like a valid file

Author: zth

analysis/src/Files.ml

@@ -96,4 +96,4 @@ let rec collect ?(checkDir = fun _ -> true) path test =
     else []
   | _ -> if test path then [path] else []
 
-let isResFile path = exists path && Filename.check_suffix path ".res"
+let isResFile path = Filename.check_suffix path ".res" && exists path