[phobos] Phobos/Druntime to 64 bit

[Walter Bright]

Yeah, that's because the CLASSINFO_SIZE changes for 64 bit, and I 
haven't accounted for that in D2 yet. I'll see about a fix.

Andrei Alexandrescu wrote:
> Whoa, I changed like a million places only to compile base64, until I 
> hit a brickwall:
>
> mismatch between dmd and object.d or object.di found. Check 
> installation and import paths with -v compiler switch.
>
> I then changed the model back to 32 bits and made sure the unittests 
> work. See the recent commit.
>
> Andrei
>