4886ec8665
This is then later used by `proc_macro` to generate a new `proc_macro::TokenTree` which preserves span information. Unfortunately this isn't a bullet-proof approach as it doesn't handle the case when there's still other attributes on the item, especially inner attributes. Despite this the intention here is to solve the primary use case for procedural attributes, attached to functions as outer attributes, likely bare. In this situation we should be able to now yield a lossless stream of tokens to preserve span information.