[truetype] Streamline backward compatibility.
The 'backward_compatibility' is only set in v40: no need to check
the interpreter version again and again. In addition, we now track
IUP in its lower bits. After both IUPx and IUPy have been called,
'backward_compatibility' becomes equal to 0x7.
* src/truetype/ttinterp.h (TT_ExecContextRec): Wrap 'iup?_called'
into 'backward_compatibility'.
* src/truetype/ttinterp.c (Ins_INSTCTRL): Sync 'backward_compatibility'.
(Direct_Move, Direct_Move_X/Y, Move_Zp2_Point,
Ins_FLIPPT,FLIPRGON,FLIPRGOFF,SHPIX,DELTAP): Updated.
(TT_RunIns): Do not mess with IUP flags.
* src/truetype/ttgload.c (tt_loader_init): Set 'backward_compatibility'.
(TT_Hint_Glyph): Updated.
3 files changed
