Level4 warning in MS Visual C++

Code:
```C++
#include

int main() {
int a = 0;
BOOST_SCOPE_EXIT(&a) {++a;} BOOST_SCOPE_EXIT_END
return 0;
}
```

When compiling with [`/W4`](https://docs.microsoft.com/en-us/cpp/build/reference/compiler-option-warning-level) in MS Visual Studio 2019, I get:
> warning C4459: declaration of 'boost_scope_exit_aux_args' hides global declaration
> …\boost\scope_exit.hpp(261,46): message : see declaration of 'boost_scope_exit_aux_args'

See also:

* [#12704 in Trac](https://svn.boost.org/trac10/ticket/12704).