[autofit] Allocate hints object on the stack.

This avoids one malloc per load.

* src/autofit/afloader.h (AF_LoaderRec): Change type of `hints' to
`AF_GlyphHints'.
Update prototype.

* src/autofit/afloader.c (af_loader_init): Use `AF_GlyphHints'
parameter instead of `FT_Memory'.
(af_loader_done): Directly reset `load_hints'.
(af_loader_load_g): Updated.

* src/autofit/afmodule.c (af_autofitter_load_glyph): Use local
`hints' object.
4 files changed