The most bespoke parts would be tool chain certification, which among other things, covers "if I have source A, then I can be sure resulting machine code does B

The most bespoke parts would be tool chain certification, which among other things, covers "if I have source A, then I can be sure resulting machine code does B, not anything else". And that's something you'll get even if you're running MS-DOS on 286 in space ;-)