Add some battle frontier constant usage

include/global.h

@@ -409,7 +409,7 @@ struct BattleFrontier
     /*0xE1A*/ u16 pyramidWinStreaks[FRONTIER_LVL_MODE_COUNT];
     /*0xE1E*/ u16 pyramidRecordStreaks[FRONTIER_LVL_MODE_COUNT];
     /*0xE22*/ u16 pyramidRandoms[4];
-    /*0xE2A*/ u8 pyramidTrainerFlags;
+    /*0xE2A*/ u8 pyramidTrainerFlags; // 1 bit for each trainer (MAX_PYRAMID_TRAINERS)
     /*0xE2C*/ struct PyramidBag pyramidBag;
     /*0xE68*/ u8 pyramidLightRadius;
     /*0xE6A*/ u16 verdanturfTentPrize;