[#103] Added VK_KHR_portability_subset requirement on apple hardware

Signed-off-by: Tobias Frisch <tfrisch@uni-koblenz.de>

src/vkcv/Context.cpp

@@ -261,6 +261,10 @@ namespace vkcv
 		
 		FeatureManager featureManager (physicalDevice);
 		
+#ifdef __APPLE__
+		featureManager.useExtension("VK_KHR_portability_subset", true);
+#endif
+		
 		if (featureManager.useExtension(VK_KHR_SHADER_FLOAT16_INT8_EXTENSION_NAME, false)) {
 			featureManager.useFeatures<vk::PhysicalDeviceShaderFloat16Int8Features>(
 					[](vk::PhysicalDeviceShaderFloat16Int8Features& features) {