[clang] [llvm] Remove experimental from Vector Crypto extensions (PR #69000)

[Eric Biggers via cfe-commits]

ebiggers wrote:

At https://github.com/ebiggers/llvm-project/tree/remove_experimental_from_vector_crypto I've rebased this pull request, squashed the commits, resolved conflicts, fixed the Zvkn duplication, and run `git clang-format`.  Note, it was necessary to change the type of `enum RVVRequire` from `uint16_t` to `unsigned int` because the next flag is now `1 << 16`, and to remove `experimental-` from some new files in `llvm/test/Transforms/` where references to the crypto extensions had been added.  @4vtomat can you update your pull request accordingly?  Feel free to reuse what I have.  Thanks!

https://github.com/llvm/llvm-project/pull/69000