[clang] [llvm] [RISC-V][RVY] Rank 'y' after 'i' and 'e' in canonical extension order (PR #227865)

[Alexander Richardson via llvm-commits]

arichardson wrote:

We definitely want it to come first initially since it's a base ISA. Regarding ordering zy* directly after zi* I am not sure if this is mandated anywhere, but I didn't want to add extra complexity to keep the order for those the same.

https://github.com/llvm/llvm-project/pull/227865