How you score that in terms of "support" I freely leave up to the reader. Go assembly does integrate into Go more than simply raw assembler would, as it handles some of the runtime concerns, so the "support" is more than just "yeah, we can write some stuff in assembler and link it in, I can do that anywhere", but on the other hand, it is a form of assembler, not something that looks like a function call in the native language or something.