Add missing Common header

projs/shadow/shadow-engine/platforms/inc/shadow/platform/Common.h

@@ -0,0 +1,22 @@
+#pragma once
+
+#ifdef __linux__
+#define ifsystem(linux,windows,apple) linux
+#elif __WIN32
+#define ifsystem(linux,windows,apple) windows
+#elif __APPLE__
+#define ifsystem(linux,windows,apple) apple
+#endif
+
+// Clang on macOS has __GNUC__ defined to 4, for some reason.
+#ifdef __clang__
+#define ifcompiler(gcc,clang,msvc) clang
+#elif __GNUC__
+#define ifcompiler(gcc,clang,msvc) gcc
+#elif _MSC_VER
+#define ifcompiler(gcc,clang,msvc) msvc
+#endif
+
+template <typename T, uint32_t count> constexpr uint32_t lengthOf(const T (&)[count]) {
+    return count;
+};