Re-apply the current layout when resizing

Re-apply the current layout when resizing

The TUI has separate code for each possible layout to handle the case
where the terminal window is resized.  With the new layout code, this
can all be replaced with a call to tui_apply_current_layout, which
simply re-applies the current layout.

This results in some small differences in behavior when resizing, so
some tests are updated.

gdb/ChangeLog
2019-12-11  Tom Tromey  <tom@tromey.com>

	* tui/tui-win.c (tui_resize_all): Remove code, call
	tui_apply_current_layout.

gdb/testsuite/ChangeLog
2019-12-11  Tom Tromey  <tom@tromey.com>

	* gdb.tui/resize.exp: Update.
	* gdb.tui/empty.exp (layouts): Update.

Change-Id: I3dc6c02a753d495d9ab5e8213d550a147198ce6f