[llvm] [Tablegen] Bugfix and refactor VarLenCodeEmitter HwModes. (PR #68795)

[Min-Yih Hsu via llvm-commits]

https://github.com/mshockwave commented:

Thanks for fixing this issue! Indeed we didn't thoroughly test the case where each HW mode has different encoding.
Could you help me to confirm that this doesn't break anything for the 68k backend, which is the only user of VarLenCodeEmitter upstream? It's not built by default and you need to use `-DLLVM_EXPERIMENTAL_TARGETS_TO_BUILD=M68k` to enable it when running cmake.
Thanks!

https://github.com/llvm/llvm-project/pull/68795