Add various typecasts (back and forth from char * to unsigned char *) to make the SGI C compiler happier (bug #445960).
Add various typecasts (back and forth from char * to unsigned char *)
to make the SGI C compiler happier (bug #445960).

sk-/python2.7-type-annotator,sk-/python2.7-type-annotator,sk-/python2.7-type-annotator