GDC with D frontend 2.081.2

[Eugene Wissner]

As some of you may know D frontend was merged into GDC some time 
ago and is up to date. D version currently supported by GDC is 
2.081.2 and it can be found in "gdc-7" and "gdc-8" branches. I 
will say a bit more about GDC development and development plans 
later.

I prepared GDC/GCC 7.3.0 binaries for x86-64 Linux built on 
Ubuntu 18.04:

https://download.dlackware.com/gdc/gdc-7.3.0_2.081.2-linux-x86_64.tar.xz

I’m not a regular Ubuntu user, and built GDC in a VM, so don't 
blame me (too much) if something doesn’t work, but let me know 
anyway. For testing I've used a minimal Ubuntu installation and 
had to install only "libc-dev" package. The package includes gcc, 
g++, gdc and standard GNU tools, but no D tools like dub. I still 
need some time to automate the building, then I can build for 
more platforms and provide some core tools.

We support several GCC versions and we still support C++-frontend 
(D version: 2.076). The reason for this is that C++-frontend 
should be merged into the next GCC version (GCC 9), then it can 
be built without another D compiler. D frontend goes into GCC 10 
and can be built with GCC 9, so GCC can be bootstrapped without 
external compilers and can be used to bootstrap other D compilers.

Current branch model. There are 2 "master" branches: master and 
stable. master contains D frontend and follows DMD master (we'll 
see if we can update every week or every two weeks). stable 
contains C++ frontend which doesn't get new D features anymore 
but of course we merge bug fixes from master. Both follow GCC 
master (master is updated weekly to GCC snapshots, stable from 
time to time).
stable has 4 derivates: gdc-8-stable, gdc-7-stable, gdc-6-stable 
and gdc-5-stable. It seems to be a lot, but the last merge from 
stable was really trivial, so the most work is done on the master 
derivates: "gdc-8" and "gdc-7" branches. These two follow DMD 
stable and contain stable D releases.