Here's a build of a quick and dirty port using software rendering. It seems to run slow, both on my o3DS and Citra.
Note that this does not include the zelda3_assets.dat, which needs to be extracted from your own (legit) ROM. Check out the original repository for more information on how to extract that.
to run, extract the zip into your /3ds/ folder, and place zelda3_assets.dat there as well. You also need to make sure your DSP firmware is dumped, or it will insta-crash.
If you want to use Citra, place the zelda3.ini file at the root of the virtual SD card, since Citra looks for it there for some reason.
To get it running at full speed, you'd probably need to re-implement the renderer using something like citro2d/citro3d for hardware acceleration.
Honestly, at this point, there is hardly any benefit of doing this over using snes9x, other than (somewhat janky) widescreen support.