Function find_last_token_span_for_name 

pub fn find_last_token_span_for_name(
    tokens: &[Token],
    name: &str,
    interner: &Interner,
) -> Option<Span>

The LAST occurrence of a name — the use-site approximation for use-after-move/escape diagnostics when no statement span is known (the complaint is always about a later use, never the binding itself).