gdb/testsuite/

	gdb/testsuite/
	* gdb.cp/formatted-ref.exp (test_p_x_ref_addr): Allow the reference
	to be in memory.
	* gdb.base/display.c (force_mem): New.
	(do_loops): Use it.  Add breakpoint comments.
	(do_vars): Add a breakpoint comment.
	* gdb.base/display.exp: Use gdb_get_line_number.  Remove hardcoded
	line numbers.