RGBDS syntax updates (#905)

New MACRO and DEF syntax

constants/gfx_constants.asm

@@ -1,48 +1,48 @@
-TILE_WIDTH EQU 8 ; pixels
-LEN_1BPP_TILE EQU 1 * TILE_WIDTH ; bytes
-LEN_2BPP_TILE EQU 2 * TILE_WIDTH ; bytes
+DEF TILE_WIDTH EQU 8 ; pixels
+DEF LEN_1BPP_TILE EQU 1 * TILE_WIDTH ; bytes
+DEF LEN_2BPP_TILE EQU 2 * TILE_WIDTH ; bytes
 
-NUM_PAL_COLORS EQU 4
-PAL_COLOR_SIZE EQU 2
-PALETTE_SIZE EQU NUM_PAL_COLORS * PAL_COLOR_SIZE
+DEF NUM_PAL_COLORS EQU 4
+DEF PAL_COLOR_SIZE EQU 2
+DEF PALETTE_SIZE EQU NUM_PAL_COLORS * PAL_COLOR_SIZE
 
-PALRGB_WHITE EQU palred 31 + palgreen 31 + palblue 31 ; $7fff
+DEF PALRGB_WHITE EQU palred 31 + palgreen 31 + palblue 31 ; $7fff
 
-SCREEN_WIDTH  EQU 20 ; tiles
-SCREEN_HEIGHT EQU 18 ; tiles
-SCREEN_WIDTH_PX  EQU SCREEN_WIDTH  * TILE_WIDTH ; pixels
-SCREEN_HEIGHT_PX EQU SCREEN_HEIGHT * TILE_WIDTH ; pixels
+DEF SCREEN_WIDTH  EQU 20 ; tiles
+DEF SCREEN_HEIGHT EQU 18 ; tiles
+DEF SCREEN_WIDTH_PX  EQU SCREEN_WIDTH  * TILE_WIDTH ; pixels
+DEF SCREEN_HEIGHT_PX EQU SCREEN_HEIGHT * TILE_WIDTH ; pixels
 
-BG_MAP_WIDTH  EQU 32 ; tiles
-BG_MAP_HEIGHT EQU 32 ; tiles
+DEF BG_MAP_WIDTH  EQU 32 ; tiles
+DEF BG_MAP_HEIGHT EQU 32 ; tiles
 
-METATILE_WIDTH EQU 4 ; tiles
-SCREEN_META_WIDTH EQU 6 ; metatiles
-SCREEN_META_HEIGHT EQU 5 ; metatiles
-SURROUNDING_WIDTH  EQU SCREEN_META_WIDTH * METATILE_WIDTH ; tiles
-SURROUNDING_HEIGHT EQU SCREEN_META_HEIGHT * METATILE_WIDTH ; tiles
-MAP_CONNECTION_PADDING_WIDTH EQU 3 ; metatiles
+DEF METATILE_WIDTH EQU 4 ; tiles
+DEF SCREEN_META_WIDTH EQU 6 ; metatiles
+DEF SCREEN_META_HEIGHT EQU 5 ; metatiles
+DEF SURROUNDING_WIDTH  EQU SCREEN_META_WIDTH * METATILE_WIDTH ; tiles
+DEF SURROUNDING_HEIGHT EQU SCREEN_META_HEIGHT * METATILE_WIDTH ; tiles
+DEF MAP_CONNECTION_PADDING_WIDTH EQU 3 ; metatiles
 
-HP_BAR_LENGTH  EQU 6 ; tiles
-EXP_BAR_LENGTH EQU 8 ; tiles
-HP_BAR_LENGTH_PX  EQU HP_BAR_LENGTH  * TILE_WIDTH ; pixels
-EXP_BAR_LENGTH_PX EQU EXP_BAR_LENGTH * TILE_WIDTH ; pixels
+DEF HP_BAR_LENGTH  EQU 6 ; tiles
+DEF EXP_BAR_LENGTH EQU 8 ; tiles
+DEF HP_BAR_LENGTH_PX  EQU HP_BAR_LENGTH  * TILE_WIDTH ; pixels
+DEF EXP_BAR_LENGTH_PX EQU EXP_BAR_LENGTH * TILE_WIDTH ; pixels
 
 ; GetHPPal return values (see home/tilemap.asm)
-HP_GREEN  EQU 0
-HP_YELLOW EQU 1
-HP_RED    EQU 2
+DEF HP_GREEN  EQU 0
+DEF HP_YELLOW EQU 1
+DEF HP_RED    EQU 2
 
 ; sprite_oam_struct members (see macros/wram.asm)
 rsreset
-SPRITEOAMSTRUCT_YCOORD     rb ; 0
-SPRITEOAMSTRUCT_XCOORD     rb ; 1
-SPRITEOAMSTRUCT_TILE_ID    rb ; 2
-SPRITEOAMSTRUCT_ATTRIBUTES rb ; 3
-SPRITEOAMSTRUCT_LENGTH EQU _RS
-NUM_SPRITE_OAM_STRUCTS EQU 40 ; see wVirtualOAM
+DEF SPRITEOAMSTRUCT_YCOORD     rb ; 0
+DEF SPRITEOAMSTRUCT_XCOORD     rb ; 1
+DEF SPRITEOAMSTRUCT_TILE_ID    rb ; 2
+DEF SPRITEOAMSTRUCT_ATTRIBUTES rb ; 3
+DEF SPRITEOAMSTRUCT_LENGTH EQU _RS
+DEF NUM_SPRITE_OAM_STRUCTS EQU 40 ; see wVirtualOAM
 
-SPRITE_GFX_LIST_CAPACITY EQU 32 ; see wUsedSprites
+DEF SPRITE_GFX_LIST_CAPACITY EQU 32 ; see wUsedSprites
 
 ; PokeAnims indexes (see engine/gfx/pic_animation.asm)
 	const_def