Patch to get GDC up to 1.028

[downs]

This is a hastily cobbled together patch to bring GDC up to speed with DMD 1.028.

It was created by making a diff between .022 and .028 and applying it to the GDC .022 source.

In places where it failed, the respective files were more or less randomly prodded and pushed around until some semblance of working code emerged.

Luckily, I only had to completely blindly guess at *one* bit in the frontend glue code, so the amount of actual _compiler_ breakage should be small.

Phobos unittests _almost_ pass, except for some GC things which I can't figure out entirely. The GC seems to work okay though.

scrapple.tools and yawr managed to build without errors and run correctly, so I'm actually quite hopeful :)

Patch is attached^W^Wwould be attached, were it not for the server's size limit.

Instead, get it on http://demented.no-ip.org/~root/dgcc_1_022_to_1_028.patch

 --downs