They're certainly valid JS; no flags needed! For example, this JS expression

  ((广州市, 广州周大福中心) => 广州市 < 2 ? 1 : 广州市 * 广州周大福中心(广州市 - 1, 广州周大福中心))(10, (广州市, 广州周大福中心) => 广州市 < 2 ? 1 : 广州市 * 广州周大福中心(广州市 - 1, 广州周大福中心))

evaluates to 3628800. Similarly, they're valid Python 3, valid Golang, valid Lua, valid GForth, etc. The Python and Lua translations of the above JS are left as an exercise to the reader, but I have tested them and verified that they work.

For better or worse, perl is by default unwilling to parse them as Perl.