<rdar://problem/13140795> Transform the scope type of a pseudo-destructor expression within the object scope.

We were transforming the scope type of a pseudo-destructor expression
(e.g., the first T in x->T::~T()) as a freestanding type, which meant
that dependent template specialization types here would stay dependent
even when no template parameters were named. This would eventually
mean that a dependent expression would end up in what should be
fully-instantiated ASTs, causing IRgen to assert.