TypeInfo for arrays seem wrong

[Chris Miller]

    if(cast(TypeInfo_Array)typeid(char[]))
       writefln("match");
    if(cast(TypeInfo_Array)typeid(typeof("hi")))
       writefln("match");

Everything's fine so far; it prints match twice. But try this from a  
variadic function and it's no longer true:

    void foo(...)
    {
       int i;
       for(i = 0; i != _arguments.length; i++)
       {
          if(cast(TypeInfo_Array)_arguments[i])
             writefln("%s matches", i);
    }

    void main()
    {
       foo(42, "hello", cast(char[])"world");
    }

and it does not match. The type of _arguments[1] ends up being TypeInfo_Aa.

The only reason why (typeid(char[]) == _arguments[i]) will work is because  
the toString() are both "char[]" which is what == on TypeInfo compares.

Solution: typeid(char[]) should be TypeInfo_Aa, and TypeInfo_Aa should  
derive from TypeInfo_Array. This goes for the other array types as well.