Go's method syntax is taken from Oberon-2, just like unsafe package is pretty much the same purpose as SYSTEM.

And, if I understand correctly, Go stole its object file format (or at least large-scale design) from Modula-2.

That I doubt it, given Modula-2 package design, how symbols are made public and type system differences.

If you mean packages as modules, other languages predate Modula-2 in that matter.

No, I mean the object file defines the public symbols at the start of the file. Go very deliberately stole that feature. Rob Pike said that using that idea let Go do something faster when compiling, though I don't remember the details.