Function emit_cursor_for_loop_facts 

pub fn emit_cursor_for_loop_facts<I>(
    store: &mut FactStore,
    prov: &FactProvenance,
    sites: I,
) -> usize
where
    I: IntoIterator<Item = CursorForLoopSite>,

Emit one CursorForLoop fact per site, mirroring emit_exception_handler_facts.