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

targets/_any/stdlib/include/stdlib.h

@@ -0,0 +1,25 @@
+
+#pragma once
+
+#if !defined(BAD_APPLE_OS_STDLIB_H_INCLUDED)
+#define BAD_APPLE_OS_STDLIB_H_INCLUDED
+
+#include <stddef.h>
+#include "./detail/common.h"
+
+BA_EXTERN_C_BEGIN
+
+BA_CXX_NORETURN void abort();
+int atexit(void (*func)()) BA_CXX_NOEXCEPT;
+BA_CXX_NODISCARD char* getenv(const char* name) BA_CXX_NOEXCEPT;
+
+BA_CXX_NODISCARD int abs(int n) BA_CXX_NOEXCEPT;
+BA_CXX_NODISCARD int atoi(const char* str) BA_CXX_NOEXCEPT;
+
+BA_CXX_NODISCARD void* calloc(size_t num, size_t size) BA_CXX_NOEXCEPT;
+BA_CXX_NODISCARD void* malloc(size_t size) BA_CXX_NOEXCEPT;
+void free(void* ptr) BA_CXX_NOEXCEPT;
+
+BA_EXTERN_C_END
+
+#endif // !defined(BAD_APPLE_OS_STDLIB_H_INCLUDED)