Don't print the entire declaration of the alliassee when `->toChars()` is called on an `AliasDeclaration`; just printing the name will do. This fixes #305, which otherwise tries to generate {{{ class E { void A() { alias /* recurse into E->toCBuffer() */ m; } } }}} by way of an infinite recursion (causing a segfault when the stack runs out).

module typeinfo3;

typedef int int_t;

void main()
{
    /*int_t i;
    auto ti = typeid(typeof(i));
    printf("%s\n",ti.toString.ptr);
    assert(ti.toString() == "typeinfo3.int_t");
    assert(ti.next !is null);
    assert(ti.next.toString() == "int");
    assert(ti.init is null);*/
}