Convert wrap_here to use integer parameter

I think it only really makes sense to call wrap_here with an argument
consisting solely of spaces.  Given this, it seemed better to me that
the argument be an int, rather than a string.  This patch is the
result.  Much of it was written by a script.

gdb/python/py-prettyprint.c

@@ -474,7 +474,7 @@ print_children (PyObject *printer, const char *hint,
 	      print_spaces_filtered (2 + 2 * recurse, stream);
 	    }
 	  else
-	    wrap_here (n_spaces (2 + 2 *recurse));
+	    wrap_here (2 + 2 *recurse);
 	}
 
       if (is_map && i % 2 == 0)