fix some file extensions

Task/Stack-traces/DWScript/stack-traces.dw

@@ -0,0 +1,21 @@
+procedure Inner;
+begin
+   try
+      raise Exception.Create('');
+   except
+      on E: Exception do
+         PrintLn(E.StackTrace);
+   end;
+end;
+
+procedure Middle;
+begin
+   Inner;
+end;
+
+procedure Outer;
+begin
+   Middle;
+end;
+
+Outer;