* gcov.c (struct line_info): Remove it's typedef.
(line_info::line_info): Add proper ctor.
(line_info::has_block): Do not use a typedef.
(struct source_info): Do not use typedef.
(circuit): Likewise.
(get_cycles_count): Likewise.
(output_intermediate_file): Iterate via vector iterator.
(add_line_counts): Use std::vector methods.
(accumulate_line_counts): Likewise.
(output_lines): Likewise.