[llvm] [RISCV] Add TuneNoDefaultUnroll to generic CPUs (PR #135318)

[Pengcheng Wang via llvm-commits]

wangpc-pp wrote:

> > > https://lnt.lukelau.me/db_default/v4/nts/665?compare_to=656
> > > Some big regression in code size with rva22u64_v -O3 -flto. Only regression in exec time was 523.xalancbmk_r but we know that benchmark is usually noisy
> > 
> > 
> > The code size regressions are expected, the performance has no observable change possibly because Spacemit X60 is just a dual-issues in-order core. I don't know if there are some data from other CPUs?
> 
> I can run this PR on a VisionFive V2 that I have available if you'd like, but it doesn't have RVV.

That'll be appreciated!

https://github.com/llvm/llvm-project/pull/135318