fix: Honor ref expressions for compute_ref_match completions

crates/ide-completion/src/context/tests.rs

@@ -391,3 +391,23 @@ fn foo($0: Foo) {}
         expect![[r#"ty: ?, name: ?"#]],
     );
 }
+
+#[test]
+fn expected_type_ref_prefix_on_field() {
+    check_expected_type_and_name(
+        r#"
+fn foo(_: &mut i32) {}
+struct S {
+    field: i32,
+}
+
+fn main() {
+    let s = S {
+        field: 100,
+    };
+    foo(&mut s.f$0);
+}
+"#,
+        expect!["ty: i32, name: ?"],
+    );
+}