Crash on Android when invoking the copy assignment operator of 'shared_library'

[RazvanAM]

When invoking the copy assignment operator (or the copy constructor) of the 'shared_library' class, eventually there is a call to 'boost::dll::detail::path_from_handle'. On android this call ends up dereferencing the handle returned by 'dlopen', which is not allowed since this patch: https://android.googlesource.com/platform/bionic/+/ae74e87%5E!/.

As a side-note, I believe the 'BOOST_OS_ANDROID' macro is not longer used.