lto: Stream edge goto_locus [PR94235]

lto: Stream edge goto_locus [PR94235]

The following patch adds streaming of edge goto_locus (both LOCATION_LOCUS
and LOCATION_BLOCK from it), the PR shows a testcase (inappropriate for
gcc testsuite) where the lack of streaming of goto_locus results in worse
debug info.
Earlier version of the patch (without the output_function changes) failed
miserably, because on the order mismatch - input_function would
first input_cfg, then input_eh_regions and then input_bb (all of which now
have locations), while output_function used output_eh_regions, then output_bb
and then output_cfg.  *_cfg went to a separate stream...
Now, is there a reason why the order is different?

If the intent is that the cfg could be read separately from the rest of
function or vice versa, alternatively we'd need to clear_line_info ();
before output_eh_regions and before/after output_cfg to make them
independent.

2020-09-07  Jakub Jelinek  <jakub@redhat.com>

	PR debug/94235
	* lto-streamer-out.c (output_cfg): Also stream goto_locus for edges.
	Use bp_pack_var_len_unsigned instead of streamer_write_uhwi to stream
	e->dest->index and e->flags.
	(output_function): Call output_cfg before output_ssa_name, rather than
	after streaming all bbs.
	* lto-streamer-in.c (input_cfg): Stream in goto_locus for edges.
	Use bp_unpack_var_len_unsigned instead of streamer_read_uhwi to stream
	in dest_index and edge_flags.