Support `_Noreturn`, `[[noreturn]]`, `__attribute__((noreturn))`

### Input C/C++ Header

C11:

```c
_Noreturn void f(void);
```

C++11 (and potentially C2x with N2764):

```c++
[[noreturn]] void f();
```

GCC & Clang:

```c
__attribute__((noreturn)) void f(void);
```

### Actual Results

```rust
extern "C" {
    pub fn f();
}
```

### Expected Results

```rust
extern "C" {
    pub fn f() -> !;
}
```