Fix FlxMacro from breaking the completion server.

Author: MAJigsaw77

source/funkin/util/macro/FlxMacro.hx

@@ -18,18 +18,30 @@ class FlxMacro
     var fields:Array<haxe.macro.Expr.Field> = haxe.macro.Context.getBuildFields();
 
     // haxe.macro.Context.info('[INFO] ${cls.name}: Adding zIndex attribute...', pos);
+    var hasZIndex = false;
 
-    // Here, we add the zIndex attribute to all FlxBasic objects.
-    // This has no functional code tied to it, but it can be used as a target value
-    // for the FlxTypedGroup.sort method, to rearrange the objects in the scene.
-    fields = fields.concat([
+    for (f in fields)
+    {
+      if (f.name == "zIndex")
       {
-        name: "zIndex", // Field name.
-        access: [haxe.macro.Expr.Access.APublic], // Access level
-        kind: haxe.macro.Expr.FieldType.FVar(macro :Int, macro $v{0}), // Variable type and default value
-        pos: pos, // The field's position in code.
+        hasZIndex = true;
+        break;
       }
-    ]);
+    }
+
+    if (!hasZIndex)
+    {
+      // Here, we add the zIndex attribute to all FlxBasic objects.
+      // This has no functional code tied to it, but it can be used as a target value
+      // for the FlxTypedGroup.sort method, to rearrange the objects in the scene.
+      fields.push(
+        {
+          name: "zIndex", // Field name.
+          access: [haxe.macro.Expr.Access.APublic], // Access level
+          kind: haxe.macro.Expr.FieldType.FVar(macro :Int, macro $v{0}), // Variable type and default value
+          pos: pos, // The field's position in code.
+        });
+    }
 
     return fields;
   }