Moved stdlib to a seperate folder and added some more headers that are required for compiling libgcc (no implementation yet).

targets/_any/stdlib/include/detail/common.h

@@ -0,0 +1,23 @@
+
+#pragma once
+
+#if !defined(BAD_APPLE_OS_DETAIL_ATTRIBUTES_H_INCLUDED)
+#define BAD_APPLE_OS_DETAIL_ATTRIBUTES_H_INCLUDED
+
+#if defined(__cplusplus)
+#define BA_CXX_NODISCARD [[nodiscard]]
+#define BA_CXX_NORETURN [[noreturn]]
+#define BA_CXX_NOEXCEPT noexcept
+#define BA_EXTERN_C_BEGIN extern "C" {
+#define BA_EXTERN_C_END }
+#define BA_C_RESTRICT
+#else
+#define BA_CXX_NODISCARD
+#define BA_CXX_NORETURN
+#define BA_CXX_NOEXCEPT
+#define BA_EXTERN_C_BEGIN
+#define BA_EXTERN_C_END
+#define BA_C_RESTRICT restrict
+#endif
+
+#endif // !defined(BAD_APPLE_OS_DETAIL_ATTRIBUTES_H_INCLUDED)