I'd be more concerned about emulators and actual chips. People have been assuming that copyright doesn't apply to APIs for so long that I'm sure there's any number of cases of accidental "copyright infringement as defined by Oracle". I'm just not sure that compilers are a prime example (at least as relating to instruction sets).
At least in the United States. China, on the other hand, will laugh at us as they lay claim to everything American lawyers prevent us from doing.
It would matter here too though as we do also want to sell software to US.
But if one stays out of US markets then things are as they have always been.
API compatibility doesn’t have any stylistic choices in it.
Silly example of course, can't think of any better. Feel free to substitute your own.
If a tree infringes in the woods and the silicon manufacturer doesn't hear it...