It also does a SETJMP and several lines of error handling, only to be followed by a block that effectively executes no code that could have use for it. So it's not only priming for something that happens somewhere else. To me it looks just as if the very call to _main itself is missing there.
And no, _main no longer uses that, that's why the function is gone. If someone wants the environment in that (bulky) form, (s)he now has to do it by converting the mapping returned by __builtin._getenv.
