Inner attributes are not allowed in inline modules

[mathstuf]

This code:

mod inline {
    #![path = "foo"]
}

is a valid way to set the path for an inline module. However, it is currently detected as a syntax error because "inner attributes are not allowed here". See #785 for existing test code which will need uncommented when this is complete.

[mathstuf]

I'm blind. I had used an inner attribute copy pasta'd into where an outer one was needed. Just could not see the #! even when the error message pointed right to the problem. 🤦