One random / recurring thought that I have had recently is: realistically, how far off are we from being able to jot down some ideas about how a given language

One random / recurring thought that I have had recently is: realistically, how far off are we from being able to jot down some ideas about how a given language should look (or use Yacc / Antlr), then have the LLM generate the compiler, LSP as well as an entire set of common libraries in the new language?