Merge pull request #10046 from Ghommie/Ghommie-cit424

Ports flag for bespoke elements.

code/datums/elements/_element.dm

@@ -1,5 +1,11 @@
 /datum/element
 	var/element_flags = NONE
+	/**
+	  * The index of the first attach argument to consider for duplicate elements
+	  * Is only used when flags contains ELEMENT_BESPOKE
+	  * This is infinity so you must explicitly set this
+	  */
+	var/id_arg_index = INFINITY
 
 /datum/element/proc/Attach(datum/target)
 	if(type == /datum/element)
@@ -19,7 +25,7 @@
 //DATUM PROCS
 
 /datum/proc/AddElement(eletype, ...)
-	var/datum/element/ele = SSdcs.GetElement(eletype)
+	var/datum/element/ele = SSdcs.GetElement(arglist(args))
 	args[1] = src
 	if(ele.Attach(arglist(args)) == ELEMENT_INCOMPATIBLE)
 		CRASH("Incompatible [eletype] assigned to a [type]! args: [json_encode(args)]")