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 arrays5;
void main()
{
    auto arr = new float[5];
    {arr[4] = 1f;}
    {assert(arr[0] !<>= 0f);}
    {assert(arr[1] !<>= 0f);}
    {assert(arr[2] !<>= 0f);}
    {assert(arr[3] !<>= 0f);}
    {assert(arr[4] == 1f);}
}