Clang doesn't accept simple braces inside a naked function

Godbolt example: https://godbolt.org/z/179z4fWc4

The braces in that example are basically a no-op (so why doesn't Clang accept them?)


```c
__attribute__((naked)) int frog()
{
    { __asm__ volatile ("mov rax, 21\n" "ret"); }
}

int main(void)
{
    int toad = frog();
    return toad;
}
```