Adding macOS detection to cmake stuff, for future planning

Author: eteran

cmake/Modules/DetectOS.cmake

@@ -5,6 +5,8 @@ elseif (CMAKE_SYSTEM_NAME MATCHES "Linux")
 	set(TARGET_PLATFORM_LINUX 1)
 elseif (CMAKE_SYSTEM_NAME MATCHES "FreeBSD")
 	set(TARGET_PLATFORM_FREEBSD 1)
+elseif (CMAKE_SYSTEM_NAME MATCHES "Darwin")
+	set(TARGET_PLATFORM_MACOS 1)
 else()
 	message(FATAL_ERROR "Unsupported OS: ${CMAKE_SYSTEM_NAME}")
 endif ()