Fix RWKV v6 model conversion

[MollySophia]

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It seems that some rwkv tensors are made FP16 rather than FP32 after specific commits. However, ggml_cuda_op_bin_bcast requires src1->type == FP32. As a result, newly converted RWKV models cannot run with cuda, while existing files aren't affected. This PR fixes the issue above.

Also add LLAMA_EXAMPLE_PERPLEXITY in the examples list of parameter --no-context-shift so that models without context shift support can do llama-perplexity again.

[ggerganov]

This is likely caused by this change where I removed the squeeze() during conversion:

https://github.com/ggerganov/llama.cpp/blob/0bf2d10c5514ff61b99897a4a5054f846e384e1e/convert_hf_to_gguf.py#L298-L301

[MollySophia]

This is likely caused by this change where I removed the squeeze() during conversion:

https://github.com/ggerganov/llama.cpp/blob/0bf2d10c5514ff61b99897a4a5054f846e384e1e/convert_hf_to_gguf.py#L298-L301

I see. So there's another way to fix this: squeeze them in rwkv6's modify_tensors(), rather than adding them to the F32 list?
Should both solve the issue. I wonder which way is better

[ggerganov]

Don't think there is any significant advantage one way or the other. Maybe squeezing in modify_tensors is a bit more localized.

[MollySophia]

Don't think there is any significant advantage one way or the other. Maybe squeezing in modify_tensors is a bit more localized.

Yeah that's what I meant. Let me change to use the more localized way then.

[ggerganov]

This is good to merge?

[MollySophia]

This is good to merge?

Yes. Thanks a lot for your time!