These checks were added because macOS doesn't have `shadow.h`, so we
would end up including our own LibC's `shadow.h` when we built Lagom.
All inclusions of this header in our code base are now guarded by
`#ifndef AK_OS_BSD_GENERIC`, so these checks are now pointless.
In C++, a function declaration with an empty parameter list means that
the function takes no arguments. In C, however, it means that the
function takes an unspecified number of parameters.
What we did previously was therefore non-conforming. This caused a
config check to fail in the curl port, as it was able to redeclare
`rand` as taking an int parameter.