Improve undefined map assembler messages (#2196)

asm/macros/event.inc

@@ -667,6 +667,14 @@
 	map \map
 	.endm
 
+	@ Set the player object's invisibility to FALSE.
+	.macro showplayer
+	.byte SCR_OP_SHOWOBJECTAT
+	.2byte LOCALID_PLAYER
+	.byte 0 @ map group
+	.byte 0 @ map num
+	.endm
+
 	@ Sets the specified object's invisibility to TRUE.
 	.macro hideobjectat localId:req, map:req
 	.byte SCR_OP_HIDEOBJECTAT
@@ -674,6 +682,14 @@
 	map \map
 	.endm
 
+	@ Set the player object's invisibility to TRUE.
+	.macro hideplayer
+	.byte SCR_OP_HIDEOBJECTAT
+	.2byte LOCALID_PLAYER
+	.byte 0 @ map group
+	.byte 0 @ map num
+	.endm
+
 	@ Turns the currently selected object (if there is one) to face the player.
 	.macro faceplayer
 	.byte SCR_OP_FACEPLAYER

asm/macros/map.inc

@@ -2,8 +2,12 @@
 
 	@ Takes a MAP constant and outputs the map group and map number as separate bytes
 	.macro map map_id:req
+	.ifdef \map_id
 	.byte \map_id >> 8    @ map group
 	.byte \map_id & 0xFF  @ map num
+	.else
+	.error "undefined map (check for typos)"
+	.endif
 	.endm
 
 	@ Defines a map script. 'type' is any MAP_SCRIPT_* constant (see include/constants/map_scripts.h)