Clang fails to silence the -Wunused-value warning in the following test-case:

```
@class Test;

#define nil2 0

#define SOMETHING(macro) macro

#define Expected(invocation) \
({ \
    SilenceWarning( \
        Test *recorder = nil2; \
        recorder; \
    ); \
})

#define SilenceWarning(macro) \
({ \
    _Pragma("clang diagnostic push") \
    _Pragma("clang diagnostic ignored \"-Wunused-value\"") \
    macro \
    _Pragma("clang diagnostic pop") \
})

int test1() {
  return 5;
}

void foo(Test *other) {
  SOMETHING(
   Expected(test1());
  )
}
```

Interestingly enough, if the use of `nil2` is replaced by `0` then the warning is suppressed correctly.