Use a predef macro that takes labels instead of juggling constants.

Besides making predefs convenient, naming a predef no longer requires
adding or renaming a predef constant. This also lets predefs be rearranged at will.

macros.asm

@@ -196,3 +196,25 @@ x = x + \1 * $40000
 	endr
 ENDM
 
+
+add_predef: MACRO
+\1Predef::
+	dw \1
+	db BANK(\1)
+ENDM
+
+predef_id: MACRO
+; Some functions load the predef id
+; without immediately calling Predef.
+	ld a, (\1Predef - PredefPointers) / 3
+ENDM
+
+predef: MACRO
+	predef_id \1
+	call Predef
+ENDM
+
+predef_jump: MACRO
+	predef_id \1
+	jp Predef
+ENDM