Defines starting with `f' in src

• FASTDARK src/p_spec.h:166
• FF_FRAMEMASK src/h2def.h:331
• FF_FULLBRIGHT src/h2def.h:330
• FINEANGLES src/h2def.h:119
• FINEMASK src/h2def.h:120
• FLIGHTTICS src/h2def.h:586
• FLOORSPEED src/p_spec.h:433
• FRACBITS src/h2def.h:139
• FRACUNIT src/h2def.h:140
• FREQ_HIGH src/i_header.h:11
• FREQ_LOW src/i_header.h:9
• FREQ_NORM src/i_header.h:10