[svn r349] Fixed problems with static arrays of void as well as a static arrays with zero length. Fixed issues with DMD generated assert statements when using class invariants, generally due to incomplete ASTs. Removed some dead code. Added a few comments.

module bug6;
class wrong { }
void bark(ref wrong s) { s = new wrong; }
void foo(wrong tree) {
    auto old = tree;
    bark(tree);
    assert(old !is tree);
}
void main()
{
    auto w = new wrong;
    auto old = w;
    foo(w);
    assert(w is old);
}