[dmd-internals] More patches for severe bugs

[Walter Bright]

Done.

Don Clugston wrote:
> These two are wrong-code bugs which are a nightmare to debug since
> they fail in subtle ways.
>
> 3560 foreach over nested function generates wrong code
> 3706 delegates of interfaces with multiple inheritance fail
>
> There's actually not so many remaining severe wrong-code bugs -- most
> of the worst ones were fixed in the past few releases.
> There are a couple of others which I am still working on (I'm finding
> them particularly difficult, which is why I've only got two in this
> list).
>
> I would also like to see this patch included in the next release,
> since it abolishes a common bug from all D code.
> 4077 Bugs caused by bitwise operator precedence
>
>