[libc++][NFC] Run clang-format on libcxx/include again (#95874)

As time went by, a few files have become mis-formatted w.r.t.
clang-format. This was made worse by the fact that formatting was not
being enforced in extensionless headers. This commit simply brings all
of libcxx/include in-line with clang-format again.

We might have to do this from time to time as we update our clang-format
version, but frankly this is really low effort now that we've formatted
everything once.

GitOrigin-RevId: e2c2ffbe7a1b5d9e32a2ce64279475b50c4cba5b
79 files changed