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).

struct Vertex {
    uint[1] c;
}

void main() {
    uint[1] c = 0xffffffff;

    auto v = Vertex(c);

    assert(v.c[0] == 0xffffffff);  // fails in LDC
}