ModelIO macOS xcode13.0 beta1

#ModelIO.framework https://github.com/xamarin/xamarin-macios/pull/12349

diff -ruN /Applications/Xcode_12.5.0.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/ModelIO.framework/Headers/MDLMaterial.h /Applications/Xcode_13.0.0-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/ModelIO.framework/Headers/MDLMaterial.h
--- /Applications/Xcode_12.5.0.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/ModelIO.framework/Headers/MDLMaterial.h	2021-03-16 08:47:24.000000000 -0400
+++ /Applications/Xcode_13.0.0-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/ModelIO.framework/Headers/MDLMaterial.h	2021-06-02 12:47:00.000000000 -0400
@@ -167,7 +167,8 @@
     MDLMaterialPropertyTypeFloat2,
     MDLMaterialPropertyTypeFloat3,
     MDLMaterialPropertyTypeFloat4,
-    MDLMaterialPropertyTypeMatrix44
+    MDLMaterialPropertyTypeMatrix44,
+    MDLMaterialPropertyTypeBuffer
 };
 
 /**
diff -ruN /Applications/Xcode_12.5.0.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/ModelIO.framework/Headers/MDLMeshBuffer.h /Applications/Xcode_13.0.0-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/ModelIO.framework/Headers/MDLMeshBuffer.h
--- /Applications/Xcode_12.5.0.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/ModelIO.framework/Headers/MDLMeshBuffer.h	2021-03-16 13:56:23.000000000 -0400
+++ /Applications/Xcode_13.0.0-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/ModelIO.framework/Headers/MDLMeshBuffer.h	2021-06-02 05:37:50.000000000 -0400
@@ -20,6 +20,7 @@
 typedef NS_ENUM(NSUInteger, MDLMeshBufferType) {
     MDLMeshBufferTypeVertex = 1,
     MDLMeshBufferTypeIndex = 2,
+    MDLMeshBufferTypeCustom = 3,
 };
 
 @protocol MDLMeshBuffer;
diff -ruN /Applications/Xcode_12.5.0.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/ModelIO.framework/Headers/MDLTypes.h /Applications/Xcode_13.0.0-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/ModelIO.framework/Headers/MDLTypes.h
--- /Applications/Xcode_12.5.0.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/ModelIO.framework/Headers/MDLTypes.h	2021-03-16 09:54:06.000000000 -0400
+++ /Applications/Xcode_13.0.0-beta.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk/System/Library/Frameworks/ModelIO.framework/Headers/MDLTypes.h	2021-06-02 11:06:38.000000000 -0400
@@ -25,9 +25,12 @@
 /* Stereolithography file format, file extension STL, UTI public.standard-tesselated-geometry-format */
 MDL_EXPORT NSString * __nonnull const kUTTypeStereolithography API_AVAILABLE(macos(10.11), ios(9.0), tvos(9.0));
 
-/* Universal Scene Description file format, file extension USDA or USDB, UTI com.pixar.universal-scene-description */
+/* Universal Scene Description file format, file extension USDA or USDC, UTI com.pixar.universal-scene-description */
 MDL_EXPORT NSString * __nonnull const kUTTypeUniversalSceneDescription API_AVAILABLE(macos(10.12), ios(10.0), tvos(9.0));
 
+/* Universal Scene Description Mobile file format, file extension USDZ, UTI com.pixar.universal-scene-description-mobile */
+MDL_EXPORT NSString * __nonnull const kUTTypeUniversalSceneDescriptionMobile API_AVAILABLE(macos(11.0), ios(14.0), tvos(14.0)); 
+
 NS_ASSUME_NONNULL_BEGIN
 typedef NS_ENUM(NSUInteger, MDLIndexBitDepth)
 {