[Qwen3-Next] Gated Delta Net

[yzh119]

https://arxiv.org/abs/2412.06464

[sricketts]

From @simon-mo: the priority here is Blackwell support (I assume SM100f).

[sricketts]

I believe this is the current progress:

Done:

• Prefill Hopper: feat: add GDN Attention #2276

WIP:

• Prefill Blackwell: chunk_gated_delta_rule for Blackwell #2340
• Decode Hopper+Blackwell: feat: [Qwen3-Next] Add Cute DSL GDN decode kernel and tests #2370