Added scripted double wild battles

asm/macros/event.inc

@@ -1778,3 +1778,21 @@
 	setfieldeffectargument 2, \priority
 	dofieldeffect FLDEFF_SPARKLE
 	.endm
+
+	@ Prepares to start a double wild battle against a species1 at Level level1 holding item1 and a species2 at Level level2 holding item2. 
+	@ Running this command will not affect normal wild battles. You start the prepared battle with dodoublewildbattle.
+	@ BUG: If the player only has one pokemon, the scripted double battle has undefined behaviours...
+	.macro setdoublewildbattle species1:req, level1:req, item1:req, species2:req, level2:req, item2:req
+	.byte 0xe3
+	.2byte \species1
+	.byte \level1
+	.2byte \item1
+	.2byte \species2
+	.byte \level2
+	.2byte \item2
+	.endm
+
+	@ Starts a wild battle against the Pokemon generated by setdoublewildbattle. Blocks script execution until the battle finishes.
+	.macro dodoublewildbattle
+	.byte 0xe4
+	.endm