Add support for hidden visibility

cranelift/object/src/backend.rs

@@ -474,6 +474,7 @@ fn translate_linkage(linkage: Linkage) -> (SymbolScope, bool) {
     let scope = match linkage {
         Linkage::Import => SymbolScope::Unknown,
         Linkage::Local => SymbolScope::Compilation,
+        Linkage::Hidden => SymbolScope::Linkage,
         Linkage::Export | Linkage::Preemptible => SymbolScope::Dynamic,
     };
     // TODO: this matches rustc_codegen_cranelift, but may be wrong.