GSL moved from stdafx.h (#1676)

Added GSL.h helper for correct including

Utilities/GSL.h

@@ -0,0 +1,14 @@
+#pragma once
+
+#define GSL_THROW_ON_CONTRACT_VIOLATION
+
+#pragma push_macro("new")
+#pragma push_macro("Expects")
+#pragma push_macro("Ensures")
+#undef new
+#undef Expects
+#undef Ensures
+#include <gsl.h>
+#pragma pop_macro("Ensures")
+#pragma pop_macro("Expects")
+#pragma pop_macro("new")

Utilities/types.h

@@ -28,6 +28,11 @@ using s16 = std::int16_t;
 using s32 = std::int32_t;
 using s64 = std::int64_t;
 
+namespace gsl
+{
+	enum class byte : std::uint8_t;
+}
+
 // Specialization with static constexpr pair<T1, T2> map[] member expected
 template<typename T1, typename T2>
 struct bijective;