demos: Make the demos work in the macOS build.

Approved-by: Henri Verbeet (@hverbeet)
Merge-Request: https://gitlab.winehq.org/wine/vkd3d/-/merge_requests/1482

include/private/quartzcore.json

@@ -0,0 +1,40 @@
+{
+    "copyright" : [
+        "Copyright 2025 Henri Verbeet",
+        "",
+        "This library is free software; you can redistribute it and/or",
+        "modify it under the terms of the GNU Lesser General Public",
+        "License as published by the Free Software Foundation; either",
+        "version 2.1 of the License, or (at your option) any later version.",
+        "",
+        "This library is distributed in the hope that it will be useful,",
+        "but WITHOUT ANY WARRANTY; without even the implied warranty of",
+        "MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU",
+        "Lesser General Public License for more details.",
+        "",
+        "You should have received a copy of the GNU Lesser General Public",
+        "License along with this library; if not, write to the Free Software",
+        "Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301, USA"
+    ],
+    "name" : "QuartzCore",
+    "interfaces" : [
+        {
+            "name" : "CAMetalLayer",
+            "class-methods" : [
+                {
+                    "selector" : "layer",
+                    "return-type" : "id"
+                }
+            ],
+            "instance-methods" : [
+                {
+                    "selector" : "release",
+                    "return-type" : "void"
+                }
+            ],
+            "properties" : [
+                {"type" : "double", "name" : "contentsScale", "float" : true}
+            ]
+        }
+    ]
+}