[llvm-branch-commits] [RISCV] Store VLMul/NF into RegisterClass's TSFlags (PR #84894)

[Wang Pengcheng via llvm-branch-commits]

https://github.com/wangpc-pp created https://github.com/llvm/llvm-project/pull/84894

This TSFlags was introduced by https://reviews.llvm.org/D108815.

We store VLMul/NF into TSFlags and add helpers to get them.

This can reduce some lines and I think there will be more usages.