Add support for /world/proc/Tick()

DMCompiler/DMStandard/Types/World.dm

@@ -113,3 +113,7 @@
 	proc/PayCredits(player, credits, note)
 		set opendream_unimplemented = TRUE
 		return 0
+
+	proc/Tick()
+		set waitfor = FALSE
+		return null

OpenDreamRuntime/DreamManager.cs

@@ -1,4 +1,5 @@
-using System.IO;
+using System.Diagnostics.CodeAnalysis;
+using System.IO;
 using System.Linq;
 using System.Text.Json;
 using DMCompiler.Bytecode;
@@ -51,11 +52,15 @@ public sealed partial class DreamManager {
         private int _dreamObjectRefIdCounter;
 
         private DreamCompiledJson _compiledJson;
+
+        [MemberNotNullWhen(true, nameof(_worldTickProc))]
         public bool Initialized { get; private set; }
         public GameTick InitializedTick { get; private set; }
 
         private ISawmill _sawmill = default!;
 
+        private DreamProc? _worldTickProc;
+
         //TODO This arg is awful and temporary until RT supports cvar overrides in unit tests
         public void PreInitialize(string? jsonPath) {
             _sawmill = Logger.GetSawmill("opendream");
@@ -95,7 +100,10 @@ public void Update() {
             if (!Initialized)
                 return;
 
-            _procScheduler.Process();
+            _procScheduler.Process(true);
+            DreamThread.Run(_worldTickProc, WorldInstance, null);
+            _procScheduler.Process(false);
+
             UpdateStat();
             _dreamMapManager.UpdateTiles();
 
@@ -132,6 +140,8 @@ public bool LoadJson(string? jsonPath) {
             // Call /world/<init>. This is an IMPLEMENTATION DETAIL and non-DMStandard should NOT be run here.
             WorldInstance.InitSpawn(new());
 
+            _worldTickProc = WorldInstance.GetProc("Tick");
+
             if (_compiledJson.Globals is GlobalListJson jsonGlobals) {
                 Globals = new DreamValue[jsonGlobals.GlobalCount];
                 GlobalNames = jsonGlobals.Names;

OpenDreamRuntime/Procs/ProcScheduler.cs

@@ -42,8 +42,10 @@ async Task Foo() {
         return task;
     }
 
-    public void Process() {
-        UpdateDelays();
+    public void Process(bool updateDelays) {
+        if (updateDelays) {
+            UpdateDelays();
+        }
 
         // Update all asynchronous tasks that have finished waiting and are ready to resume.
         //