[llvm] [RISCV] Only allow up to e64 in vsetvli (PR #92010)

[Jessica Clarke via llvm-commits]

jrtc27 wrote:

https://github.com/llvm/llvm-project/commit/66da87dcbaf91fa3393ce80c687e9c2d133ee3ca is the commit that first introduced this check which was committed just after V 0.9 (haven't checked if it implemented 0.9 or stuck with 0.8), and up until 1.0 64 < SEW <= 1024 was reserved (see https://github.com/riscv/riscv-v-spec/commit/c32b714b9c4f9f85cb647791939906fba407ab87).

https://github.com/llvm/llvm-project/pull/92010