Realized I forgot to give it, so in case it's important, the context here is the black test suite:

https://github.com/psf/black/issues/1441

that test suite has a file full of expressions that it expects to be able to parse this way (it uses `ast.parse()`, which in turn calls `compile()` with this flag). A bare (*starred) line is part of that file:

https://github.com/psf/black/blob/master/tests/data/expression.py#L149

and has been for as long as black has existed. Presumably if this isn't going to be fixed we'll need to adapt this black test file to test a starred expression in a 'valid' way, somehow.