Update harfbuzz to 1.1.2:

Overview of changes leading to 1.1.2
Wednesday, November 26, 2015
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- Fix badly-broken fallback shaper that affected terminology.
  https://github.com/behdad/harfbuzz/issues/187
- Fix y_scaling in Graphite shaper.
- API changes:
  * An unset glyph_h_origin() function in font-funcs now (sensibly)
    implies horizontal origin at 0,0.  Ie, the nil callback returns
    true instead of false.  As such, implementations that have a
    glyph_h_origin() that simply returns true, can remove that function
    with HarfBuzz >= 1.1.2.  This results in a tiny speedup.

(wiz)