Fix hb_in_range() for types smaller than int

As exercised by hb-coretext .notdef code.
[coretext] Fix last range

Test with:

hb-view /Library/Fonts/Zapfino.ttf ZapfinoZapfino --features=-dlig[7:] --shaper=coretext
[coretext] Fix fallback detection

Fixes http://github.com/behdad/harfbuzz/pull/36