Determinism isn't the main hurdle. It would be a moderate effort to engineer a deterministic claude that would be no more useful than the current one.

The key characteristic of a compiler is that it takes a source language with a well-defined meaning to a target language with a well-defined meaning.

The reason claude fails to be a compiler is that its input language (english) can't be precisely defined. (And even if that were possible, it would very often fail to preserve the meaning when "compiling")