[type1] Fix signedness issues.

* include/internal/psaux.h, include/internal/t1types.h,
src/psaux/psobjs.c, src/psaux/psobjs.h, src/psaux/t1decode.c,
src/type1/t1gload.c, src/type1/t1load.c, src/type1/t1parse.c: Apply.
9 files changed