gdb/

	gdb/
	* tracepoint.c: Include stack.h.
	(struct add_local_symbols_data): New.
	(do_collect_symbol): New.
	(add_local_symbols): Rewrite using iterate_over_block_arg_vars and
	iterate_over_block_local_vars.
	* stack.c (print_block_frame_locals): Rewrite as ...
	(iterate_over_block_locals): ... this.  Take a callback function
	pointer and generic data pointer, and call that instead of
	print_variable_and_value.
	(struct print_variable_and_value_data): New.
	(do_print_variable_and_value): New.
	(iterate_over_block_local_vars): New, abstracted out from
	print_frame_local_vars.
	(print_frame_local_vars): Rewrite using
	iterate_over_block_local_vars.
	(iterate_over_block_arg_vars): New, abstracted out from
	print_frame_arg_vars.
	(print_frame_arg_vars): Rewrite using iterate_over_block_arg_vars.
	* stack.h (iterate_over_block_arg_local_vars_cb): New typedef.
	(iterate_over_block_arg_vars, iterate_over_block_local_vars): Declare.

	gdb/testsuite/
	* gdb.trace/collection.c (local_test_func): Define a local struct,
	and instanciate it.