RGBDS syntax updates (#905)

New MACRO and DEF syntax

engine/link/mystery_gift.asm

@@ -1,28 +1,28 @@
 ; hMGRole values
-IR_RECEIVER EQU 1
-IR_SENDER   EQU 2
+DEF IR_RECEIVER EQU 1
+DEF IR_SENDER   EQU 2
 
 ; hMGStatusFlags error bits
-MG_WRONG_CHECKSUM_F EQU 0
-MG_TIMED_OUT_F      EQU 1
-MG_CANCELED_F       EQU 4
-MG_WRONG_PREFIX_F   EQU 7
+DEF MG_WRONG_CHECKSUM_F EQU 0
+DEF MG_TIMED_OUT_F      EQU 1
+DEF MG_CANCELED_F       EQU 4
+DEF MG_WRONG_PREFIX_F   EQU 7
 
 ; hMGStatusFlags values
-MG_WRONG_CHECKSUM EQU 1 << MG_WRONG_CHECKSUM_F
-MG_TIMED_OUT      EQU 1 << MG_TIMED_OUT_F
-MG_CANCELED       EQU 1 << MG_CANCELED_F
-MG_WRONG_PREFIX   EQU 1 << MG_WRONG_PREFIX_F
-MG_NOT_OKAY       EQU MG_WRONG_CHECKSUM | MG_TIMED_OUT | MG_CANCELED | MG_WRONG_PREFIX
-MG_OKAY           EQU ~MG_NOT_OKAY
-MG_START_END      EQU %11111111
+DEF MG_WRONG_CHECKSUM EQU 1 << MG_WRONG_CHECKSUM_F
+DEF MG_TIMED_OUT      EQU 1 << MG_TIMED_OUT_F
+DEF MG_CANCELED       EQU 1 << MG_CANCELED_F
+DEF MG_WRONG_PREFIX   EQU 1 << MG_WRONG_PREFIX_F
+DEF MG_NOT_OKAY       EQU MG_WRONG_CHECKSUM | MG_TIMED_OUT | MG_CANCELED | MG_WRONG_PREFIX
+DEF MG_OKAY           EQU ~MG_NOT_OKAY
+DEF MG_START_END      EQU %11111111
 
-REGION_PREFIX EQU $96
-REGION_CODE   EQU $90 ; USA
+DEF REGION_PREFIX EQU $96
+DEF REGION_CODE   EQU $90 ; USA
 
-MESSAGE_PREFIX EQU $5a
+DEF MESSAGE_PREFIX EQU $5a
 
-NAME_CARD_PREFIX EQU $3c
+DEF NAME_CARD_PREFIX EQU $3c
 
 DoMysteryGift:
 	call ClearTilemap