[truetype] Make `avar2` optional
- include/freetype/config/ftoption.h (TT_CONFIG_AVAR_FORMAT_2): Add a default-disabled option for enabling avar2 support.
- src/truetype/ttgxvar.c (ft_var_load_avar): Only load avar2 when option
TT_CONFIG_AVAR_FORMAT_2
is enabled.
Edited by Dominik Röttsches