Added initial defines header

Signed-off-by: Robear Selwans <robear.selwans@outlook.com>

defines.h

@@ -0,0 +1,30 @@
+#pragma once
+
+// Operating System Detection
+#if defined(_WIN32)
+# define EV_OS_WINDOWS
+#elif defined(__linux__)
+# define EV_OS_LINUX
+#elif defined(__APPLE__)
+# include "TargetConditionals.h"
+# if defined(TARGET_OS_IPHONE)
+#  define EV_OS_IOS
+# elif defined(TARGET_OS_MAC)
+#  define EV_OS_MACOS
+# elif defined(__ANDROID__)
+#  define EV_OS_ANDROID
+# endif
+#else
+# error EV_OS_UNKNOWN
+#endif
+
+// Compiler Detection
+#if defined(_MSC_VER)
+# define EV_CC_MSVC
+#elif defined(__GNUC__)
+# define EV_CC_GCC
+#elif defined(__clang)
+# define EV_CC_CLANG
+#else
+# error EV_CC_UNKNOWN
+#endif