Use plain stat instead of safe_stat.

Use plain stat instead of safe_stat.
(find_semicolon): Function removed.
(read_makefile): Don't use find_semicolon or remove_comments for rule lines.
Use find_char_unquote directly and handle quoted comments properly.
(multi_glob): Call dir_setup_glob on our glob_t and use GLOB_ALTDIRFUNC flag.