Function find_declaration_cross_file 

pub fn find_declaration_cross_file(
    files: &HashMap<PathBuf, String>,
    current_uri: &Url,
    name: &str,
) -> Option<CrossFileSymbol>

Find name’s declaration in any project file other than current_uri. files is a pre-read (path, content) map (content-ownership track, #1086, slice 1) — see bynk_ide::symbols::find_declaration_cross_file for the pure logic.