Constant clippy_utils::macros::AST_FORMAT_ARGS

const AST_FORMAT_ARGS: LocalKey<RefCell<FxHashMap<Span, FormatArgs>>>;

We preserve the FormatArgs structs from the early pass for use in the late pass to be able to access the many features of a LateContext.

A thread local is used because FormatArgs is !Send and !Sync, we are making an assumption that the early pass that populates the map and the later late passes will all be running on the same thread.