bool vector int width fixes

bool vector int width fixes

* data.c (bool_vector_spare_mask, Fbool_vector_count_matches)
(Fbool_vector_count_matches_at):
Use EMACS_INT, not ptrdiff_t, to record bit counts, as a bit count
can exceed PTRDIFF_MAX, at least in theory.
(Fbool_vector_count_matches_at):
Use int, not ptrdiff_t, to record a value that can't exceed INT_MAX.