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

[Paul Walker via cfe-commits]

paulwalker-arm wrote:

What's the advantage of moving away from the current implementation?  From what I can see we're now having to add knowledge about what's essentially a target specific type across common code, which the current implementation avoids.

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