What is the type of a named rvalue reference?

Consider the following code:

int&& x = 42;
static_assert(std::is_same<decltype( x ), int&&>::value, "&&");
static_assert(std::is_same<decltype((x)), int& >::value, "&" );

So, what is the type of x? Is it an int&& or an int&?

(I asked myself this question after reading this answer.)