Emit warning when named arguments are used positionally in format Addresses Issue 98466 by emitting an error if a named argument is used like a position argument (i.e. the name is not used in the string to be formatted). Fixes rust-lang#98466
MutVisitor::token_visiting_enabled
CursorRef
Tree
TokenStream::from_streams
debugging_opts
unstable_opts
rustc_lint_diagnostics
crate
&str
String
MultiSpan::push_span_label