I'm getting an error compiling code that assumes gnu atomic builtins are present, such as `__atomic_load_n`. Reduced:

```
#ifdef __TINYC__
#elif defined(_WIN32)
#else
int atomic_load(const volatile int *p)
{
#ifdef __ATOMIC_RELAXED
    return __atomic_load_n(p, __ATOMIC_RELAXED);
#endif
}
#endif

```

```
Error: undefined identifier `__atomic_load_n`
```

Other builtins: https://gcc.gnu.org/onlinedocs/gcc/_005f_005fatomic-Builtins.html