Revert "[MIRROR] Replace all secondary flags with bitflags stored in the flags_2 var" (#2457)

ok you know what yeah i think i'll properly mirror https://github.com/Citadel-Station-13/Citadel-Station-13/pull/2411

code/controllers/subsystem/shuttle.dm

@@ -5,7 +5,7 @@ SUBSYSTEM_DEF(shuttle)
 	name = "Shuttle"
 	wait = 10
 	init_order = INIT_ORDER_SHUTTLE
-	flags_1 = SS_KEEP_TIMING|SS_NO_TICK_CHECK
+	flags = SS_KEEP_TIMING|SS_NO_TICK_CHECK
 	runlevels = RUNLEVEL_SETUP | RUNLEVEL_GAME
 
 	var/list/mobile = list()
@@ -84,7 +84,7 @@ SUBSYSTEM_DEF(shuttle)
 		var/turf/T = i
 		T.ChangeTurf(/turf/open/space)
 		transit_turfs += T
-		T.flags_1 |= UNUSED_TRANSIT_TURF_1
+		T.flags |= UNUSED_TRANSIT_TURF
 
 #ifdef HIGHLIGHT_DYNAMIC_TRANSIT
 /datum/controller/subsystem/shuttle/proc/color_space()
@@ -412,13 +412,13 @@ SUBSYSTEM_DEF(shuttle)
 		for(var/i in transit_turfs)
 			CHECK_TICK
 			var/turf/topleft = i
-			if(!(topleft.flags_1 & UNUSED_TRANSIT_TURF_1))
+			if(!(topleft.flags & UNUSED_TRANSIT_TURF))
 				continue
 			var/turf/bottomright = locate(topleft.x + transit_width,
 				topleft.y + transit_height, topleft.z)
 			if(!bottomright)
 				continue
-			if(!(bottomright.flags_1 & UNUSED_TRANSIT_TURF_1))
+			if(!(bottomright.flags & UNUSED_TRANSIT_TURF))
 				continue
 
 			proposed_zone = block(topleft, bottomright)
@@ -428,7 +428,7 @@ SUBSYSTEM_DEF(shuttle)
 				var/turf/T = j
 				if(!T)
 					continue base
-				if(!(T.flags_1 & UNUSED_TRANSIT_TURF_1))
+				if(!(T.flags & UNUSED_TRANSIT_TURF))
 					continue base
 			//to_chat(world, "[COORD(topleft)] and [COORD(bottomright)]")
 			break base
@@ -500,7 +500,7 @@ SUBSYSTEM_DEF(shuttle)
 	for(var/i in new_transit_dock.assigned_turfs)
 		var/turf/T = i
 		T.ChangeTurf(transit_path)
-		T.flags_1 &= ~(UNUSED_TRANSIT_TURF_1)
+		T.flags &= ~(UNUSED_TRANSIT_TURF)
 
 	M.assigned_transit = new_transit_dock
 	return TRUE