As you point out, the important bit is the documentation that shows how and why a language is compliant with a safety standard. The spec serves as the basis on

As you point out, the important bit is the documentation that shows how and why a language is compliant with a safety standard. The spec serves as the basis on which the compliance can be referenced. A given implementation then is shown to satisfy the spec. So yes, a given vanilla release is compliant, you just can't do anything with that in a way that an audit will allow until you include all the justifications as to how that makes the language safe (defined by whatever safety standard you need).