various: translation resources from cg backend

Extend `CodegenBackend` trait with a function returning the translation
resources from the codegen backend, which can be added to the complete
list of resources provided to the emitter.

Signed-off-by: David Wood <david.wood@huawei.com>

src/lib.rs

@@ -172,6 +172,11 @@ pub struct CraneliftCodegenBackend {
 }
 
 impl CodegenBackend for CraneliftCodegenBackend {
+    fn locale_resource(&self) -> &'static str {
+        // FIXME(rust-lang/rust#100717) - cranelift codegen backend is not yet translated
+        ""
+    }
+
     fn init(&self, sess: &Session) {
         use rustc_session::config::Lto;
         match sess.lto() {