Choosing a non-default linker for dmd (via dub)

[Per Nordlöw]

The line

dflags "-linker=gold" platform="linux-ldc" # use GNU gold linker

in dub.sdl

enables me to change linker for LDC.

Is it possible to choose a specific linker for DMD aswell in a 
similar way?

I only find the flag `-L` that sets flags but no linker 
executable.

One way is to link

     /usr/bin/ld

to either

     /usr/bin/ld.gold

or

     /usr/bin/ld.lld

but it would be nice to be able to do this from the dub.sdl or 
the command-line call to dub.