[libcxx-commits] [libcxx] [libc++][NFC] Fixed some wrongly spelled `_LIBCPP_STD_VER` in comments (PR #147008)

[A. Jiang via libcxx-commits]

https://github.com/frederick-vs-ja approved this pull request.

LGTM (with CI becoming green enough)

https://github.com/llvm/llvm-project/pull/147008