[clang] [NFC][Clang][AArch64]Refactor implementation of Neon vectors MFloat8… (PR #114804)

[Paul Walker via cfe-commits]

https://github.com/paulwalker-arm approved this pull request.

Looks good but please remember to update the commit message to reflect the PR as it stands today.

https://github.com/llvm/llvm-project/pull/114804