gdb/

	gdb/
	* tracepoint.c (tfile_read): New.
	(tfile_open): Use it.
	(tfile_get_traceframe_address): Use it.
	(tfile_trace_find): Use it.
	(walk_blocks_callback_func): New typedef.
	(match_blocktype): New function.
	(traceframe_walk_blocks): New function.
	(traceframe_find_block_type): New function.
	(tfile_fetch_registers, tfile_xfer_partial)
	(tfile_get_trace_state_variable_value): Use
	traceframe_find_block_type and tfile_read.