chore: add test case for nested use tree

Author: Young-Flash

crates/ide-assists/src/handlers/remove_unused_imports.rs

@@ -536,6 +536,79 @@ mod y {
         );
     }
 
+    #[test]
+    fn remove_unused_auto_remove_brace_nested() {
+        check_assist(
+            remove_unused_imports,
+            r#"
+mod a {
+    pub struct A();
+}
+mod b {
+    struct F();
+    mod c {
+        $0use {{super::{{
+            {d::{{{{{{{S, U}}}}}}}},
+            {{{{e::{H, L, {{{R}}}}}}}},
+            F, super::a::A
+        }}}};$0
+        fn f() {
+            let f = F();
+            let l = L();
+            let a = A();
+            let s = S();
+            let h = H();
+        }
+    }
+
+    mod d {
+        pub struct S();
+        pub struct U();
+    }
+
+    mod e {
+        pub struct H();
+        pub struct L();
+        pub struct R();
+    }
+}
+"#,
+            r#"
+mod a {
+    pub struct A();
+}
+mod b {
+    struct F();
+    mod c {
+        use super::{
+            d::S,
+            e::{H, L},
+            F, super::a::A
+        };
+        fn f() {
+            let f = F();
+            let l = L();
+            let a = A();
+            let s = S();
+            let h = H();
+        }
+    }
+
+    mod d {
+        pub struct S();
+        pub struct U();
+    }
+
+    mod e {
+        pub struct H();
+        pub struct L();
+        pub struct R();
+    }
+}
+"#,
+        );
+    }
+
     #[test]
     fn remove_nested_all_unused() {
         check_assist(