[truetype] Relocate subpixel flag setting. `TT_RunIns` is too busy to deal with subpixel flags. It is better to set them in `tt_loader_init`, which is executed before each glyph program. * src/truetype/ttinterp.c (TT_RunIns): Move the flag setting from here... * src/truetype/ttgload.c (tt_loader_init): ... to here.