Fix macOS 10.15.5 with Xcode 12.1 compilation error.
diff --git a/MoltenVK/MoltenVK/API/mvk_datatypes.h b/MoltenVK/MoltenVK/API/mvk_datatypes.h
index 12628c5..869bf17 100644
--- a/MoltenVK/MoltenVK/API/mvk_datatypes.h
+++ b/MoltenVK/MoltenVK/API/mvk_datatypes.h
@@ -292,7 +292,7 @@
  */
 MTLSamplerAddressMode mvkMTLSamplerAddressModeFromVkSamplerAddressMode(VkSamplerAddressMode vkMode);
 
-#ifdef __MAC_OS_X_VERSION_MAX_ALLOWED
+#if MVK_MACOS_OR_IOS 
 /**
  * Returns the Metal MTLSamplerBorderColor corresponding to the specified Vulkan VkBorderColor,
  * or returns MTLSamplerBorderColorTransparentBlack if no corresponding MTLSamplerBorderColor exists.
diff --git a/MoltenVK/MoltenVK/GPUObjects/MVKDevice.mm b/MoltenVK/MoltenVK/GPUObjects/MVKDevice.mm
index eb7f5f1..9148fbe 100644
--- a/MoltenVK/MoltenVK/GPUObjects/MVKDevice.mm
+++ b/MoltenVK/MoltenVK/GPUObjects/MVKDevice.mm
@@ -1409,11 +1409,11 @@
     if ( [_mtlDevice respondsToSelector: @selector(areRasterOrderGroupsSupported)] ) {
         _metalFeatures.rasterOrderGroups = _mtlDevice.rasterOrderGroupsSupported;
     }
-
+#if MVK_XCODE_12
 	if ( [_mtlDevice respondsToSelector: @selector(supportsPullModelInterpolation)] ) {
 		_metalFeatures.pullModelInterpolation = _mtlDevice.supportsPullModelInterpolation;
 	}
-
+#endif
     if ( [_mtlDevice respondsToSelector: @selector(maxBufferLength)] ) {
         _metalFeatures.maxMTLBufferSize = _mtlDevice.maxBufferLength;
     }
diff --git a/MoltenVK/MoltenVK/Vulkan/mvk_datatypes.mm b/MoltenVK/MoltenVK/Vulkan/mvk_datatypes.mm
index 9508f5d..f348b54 100644
--- a/MoltenVK/MoltenVK/Vulkan/mvk_datatypes.mm
+++ b/MoltenVK/MoltenVK/Vulkan/mvk_datatypes.mm
@@ -291,7 +291,7 @@
 	}
 }
 
-#if MVK_MACOS
+#if MVK_MACOS_OR_IOS
 MVK_PUBLIC_SYMBOL MTLSamplerBorderColor mvkMTLSamplerBorderColorFromVkBorderColor(VkBorderColor vkColor) {
 	switch (vkColor) {
 		case VK_BORDER_COLOR_FLOAT_TRANSPARENT_BLACK:	return MTLSamplerBorderColorTransparentBlack;