Merge pull request #653 from CeladonSS13/upstream-pr-3053

[MIRROR] Ports a super small TG signal optimization

code/datums/components/_component.dm

@@ -321,10 +321,12 @@
 	// all the objects that are receiving the signal get the signal this final time.
 	// AKA: No you can't cancel the signal reception of another object by doing an unregister in the same signal.
 	var/list/queued_calls = list()
-	for(var/datum/listening_datum as anything in target)
-		queued_calls[listening_datum] = listening_datum.signal_procs[src][sigtype]
-	for(var/datum/listening_datum as anything in queued_calls)
-		. |= call(listening_datum, queued_calls[listening_datum])(arglist(arguments))
+	// This should be faster than doing `var/datum/listening_datum as anything in target` as it does not implicitly copy the list
+	for(var/i in 1 to length(target))
+		var/datum/listening_datum = target[i]
+		queued_calls.Add(listening_datum, listening_datum.signal_procs[src][sigtype])
+	for(var/i in 1 to length(queued_calls) step 2)
+		. |= call(queued_calls[i], queued_calls[i + 1])(arglist(arguments))
 
 // The type arg is casted so initial works, you shouldn't be passing a real instance into this
 /**