gcov.c: Comments updated.

gcov.c: Comments updated.

	* gcov.c: Comments updated.
	(source_info): Add file_time field.
	(source_index): New variable.
	(mutiple_files): New variable.
	(generate_results): New function extracted from process_file.
	(process_file): Save and restore chain of functions, generate
	results and free structures only if not merging results.
	(release_structures): File names are now freed in create_file_names
	(create_file_names): Free previous file names.
	(find_source): File date is now read here and modifications in
	source files is checked here.
	(read_graph_file): Only reverse order of functions for the current
	object file.
	(make_gcov_file_name): Do not generate long names if input_name is
	NULL.
	(output_lines): If merging results do not display graph, data and
	runs informations.
	Checking source file modification is done in find_source.

	* doc/gcov.texi: Append an s to sourcefile.

From-SVN: r125649