Add Mac platform

Source/Engine/Platform/Mac/MacDefines.h

@@ -0,0 +1,19 @@
+// Copyright (c) 2012-2021 Wojciech Figat. All rights reserved.
+
+#pragma once
+
+#if PLATFORM_MAC
+
+// Platform description
+#define PLATFORM_64BITS 1
+#define PLATFORM_ARCH_X64 1
+#define PLATFORM_ARCH ArchitectureType::x64
+#define PLATFORM_TYPE PlatformType::Mac
+#define PLATFORM_DESKTOP 1
+#define PLATFORM_CACHE_LINE_SIZE 128
+#define PLATFORM_HAS_HEADLESS_MODE 1
+#define PLATFORM_DEBUG_BREAK __builtin_trap()
+#define PLATFORM_LINE_TERMINATOR "\n"
+#define PLATFORM_TEXT_IS_CHAR16 1
+
+#endif