GCOV: print {start,end}_column in JSON file and gcov-dump tool.

GCOV: print {start,end}_column in JSON file and gcov-dump tool.

2019-03-14  Martin Liska  <mliska@suse.cz>

	* coverage.c (coverage_begin_function): Stream also
	end_column.
	* doc/gcov.texi: Document 2 new fields in JSON file.  Improve
	documentation about function declaration location.
	* gcov-dump.c (tag_function): Print whole range
	of function declaration.
	* gcov.c (struct function_info): Add end_column field.
	(function_info::function_info): Initialize it.
	(output_json_intermediate_file): Output {start,end}_column
	fields.
	(read_graph_file): Read end_column.

From-SVN: r269678