Expression involving function type is lvalue or rvalue?

void fn() {}
void (&lref)() = fn;
void (&&rref)() = fn;

int main() {}

Compiles well under g++ 4.8.1.

So, fn is an expression, and an expression must have a category according to the ISO standard. Which category then the expression belongs before any automatic type promotion since both references can accept the result of evaluating the expression fn?