[svn r183] Fixed broken identity expressions with two pointers of different types. Fixed broken pointer arithmetic for subtraction (tango.text.Util unittest now passes)

module complex3;

void main()
{
    cfloat c1 = 1f + 0i;
    cfloat c2 = 0f + 0i;
    c2 += 1f + 0i;
    //assert(c1 == c2);
}