druntime

[bioinfornatics]

Hi,
If i understand druntime from github is main part of library, but for build
druntime with ldc by example ldc add specific part, maybe is same for gdc.
It will better to add these specific part to main druntime and do something like:
make dc=dmd
make install
-- or --
make dc=ldc
make install
-- or --
make dc=gdc
make install

This will be very helpful for me and packaging a D2 environnement

thanks