[clang] [clang-tools-extra] [llvm] [mlir] [emacs] Fix Emacs library formatting (PR #76110)

[Owen Pan via cfe-commits]

owenca wrote:

@darkfeline I'm ok with adding the Version comment in clang/tools/clang-format/clang-format.el, but you may have to explicitly request others to review the rest of the patch.

https://github.com/llvm/llvm-project/pull/76110