Prohibit inner scope type definition

compiler/erg_compiler/error.rs

@@ -1296,6 +1296,24 @@ passed keyword args:    {RED}{kw_args_len}{RESET}"
     pub fn file_error(errno: usize, desc: String, loc: Location, caused_by: AtomicStr) -> Self {
         Self::new(ErrorCore::new(errno, IoError, loc, desc, None), caused_by)
     }
+
+    pub fn inner_typedef_error(errno: usize, loc: Location, caused_by: AtomicStr) -> Self {
+        Self::new(
+            ErrorCore::new(
+                errno,
+                TypeError,
+                loc,
+                switch_lang!(
+                    "japanese" => format!("型はトップレベルで定義されなければなりません"),
+                    "simplified_chinese" => format!("类型必须在顶层定义"),
+                    "traditional_chinese" => format!("類型必須在頂層定義"),
+                    "english" => format!("types must be defined at the top level"),
+                ),
+                None,
+            ),
+            caused_by,
+        )
+    }
 }
 
 #[derive(Debug)]