bpo-35879: Fix type comment leaks (GH-11728)

* Fix leak for # type: ignore
* Fix the type comment leak
diff --git a/Parser/parsetok.c b/Parser/parsetok.c
index 7fddc5a..1fa4a12 100644
--- a/Parser/parsetok.c
+++ b/Parser/parsetok.c
@@ -330,6 +330,7 @@
         }
 
         if (type == TYPE_IGNORE) {
+            PyObject_FREE(str);
             if (!growable_int_array_add(&type_ignores, tok->lineno)) {
                 err_ret->error = E_NOMEM;
                 break;
diff --git a/Python/ast.c b/Python/ast.c
index c422e96..45578a8 100644
--- a/Python/ast.c
+++ b/Python/ast.c
@@ -699,11 +699,16 @@
 */
 
 static string
-new_type_comment(const char *s)
+new_type_comment(const char *s, struct compiling *c)
 {
-  return PyUnicode_DecodeUTF8(s, strlen(s), NULL);
+    PyObject *res = PyUnicode_DecodeUTF8(s, strlen(s), NULL);
+    if (PyArena_AddPyObject(c->c_arena, res) < 0) {
+        Py_DECREF(res);
+        return NULL;
+    }
+    return res;
 }
-#define NEW_TYPE_COMMENT(n) new_type_comment(STR(n))
+#define NEW_TYPE_COMMENT(n) new_type_comment(STR(n), c)
 
 static int
 num_stmts(const node *n)