ide: add a new test

crates/ide/src/references.rs

@@ -350,6 +350,27 @@ fn test() {
         );
     }
 
+    #[test]
+    fn test_access() {
+        check(
+            r#"
+struct S { f$0: u32 }
+
+#[test]
+fn test() {
+    let mut x = S { f: 92 };
+    x.f = 92;
+}
+"#,
+            expect![[r#"
+                f Field FileId(0) 11..17 11..12
+
+                FileId(0) 61..62 read test
+                FileId(0) 76..77 write test
+            "#]],
+        );
+    }
+
     #[test]
     fn test_struct_literal_after_space() {
         check(