Oh! I didn't know you were actively working on packaging these. I've also packaged them, with results in the debian-unstable branches of these github repositories:
I think it's obviously better (since you're a dd, and I'm not) for you to own it, so feel free to take any bits you find useful from those repositories. The glslang packaging mostly came from some work that had already been done by Daan Wendelen, and he asked that his name/copyright remain attached to it, so if you use some of that, please honor his request. He also gave me permission to change the license for debian/* to Apache-2.0, so I did.
Some other bits you may not be aware of:
John Kessenich (main maintainer of glslang) is working on coming up with a reasonable versioning scheme for it. So until he does that, you may want to use a scheme similar to what I did, that will be overridden with whatever he comes up with. The bug to track what he's doing is here:
I'm also working on packaging VulkanTools, and am running into a problem I think you will also run into packaging the LVL repository. I have to run right now, but I'll send you more details later, when I figure out how to get around it.
Thanks!