and by DSL they mean "extension language". like vimscript or emacs lisp. or guile or python...
so you can easily add primitives to your application specific language, in go, specifically.
https://gitlab.com/gitlab-org/vulnerability-research/foss/li...
I think this fits nearly with the common understanding "DSL" doesn't it?
https://en.m.wikipedia.org/wiki/Domain-specific_language