I am not suggesting the use of LLMs to replace compilers. I am proposing LLMs transforming detailed text-based specifications and design documents into code.

As for your understanding of how LLMs and compilers work, it does not match my experience working on either one, back in the day. I humbly suggest reading some of the literature on reproducible builds, as well as the conditions under which LLM inference is/isn't deterministic, as it is more complex than most people understand.