[clang] [RISCV] Split out the intrinsic tests for bfloat16 into a separate directory named zvfbfmin. NFC. (PR #147644)

[Brandon Wu via cfe-commits]

https://github.com/4vtomat approved this pull request.

I agree with you that it's easier to maintain, btw are you going to do that for all extensions?

https://github.com/llvm/llvm-project/pull/147644