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

[Craig Topper via llvm-commits]

https://github.com/topperc commented:

Do we need to add the "experimental" feature to RISCVFeatures.td? If the feature string shows up in the function attributes, won't the backend print that it doesn't recognize the feature name when it parses the string?

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