[backend]将testdata/下的测例替换为了赛方测试用例，更新了测试脚本

testdata/functional/34_arr_expr_len.sy

@@ -0,0 +1,11 @@
+//const int N = -1;
+int arr[-1 + 2 * 4 - 99 / 99] = {1, 2, 33, 4, 5, 6};
+
+int main() {
+  int i = 0, sum = 0;
+  while (i < 6) {
+    sum = sum + arr[i];
+    i = i + 1;
+  }
+  return sum;
+}