[vLLM-ATOM] Support EAGLE3 spec decoding for MiniMax-M3

[kliuae]

Motivation

This PR adds EAGLE 3/3.1 speculative decoding support for MiniMax-M3 in vllm-atom.
It depends on and currently contains changes from #1201, and will be rebased once the dependency gets merged.

Technical Details

Test Plan

Target model: MiniMaxAI/MiniMax-M3-MXFP8
Draft model: Inferact/MiniMax-M3-EAGLE3

Server command

VLLM_ROCM_USE_AITER=1 VLLM_USE_V1=1 \
vllm serve MiniMaxAI/MiniMax-M3-MXFP8 \
    --host localhost \
    --port 8000 \
    --no-trust-remote-code \
    --dtype auto \
    --kv-cache-dtype auto \
    --max-model-len 32768 \
    --max-num-batched-tokens 32768 \
    --no-enable-prefix-caching \
    --compilation-config '{"cudagraph_mode": "FULL_AND_PIECEWISE"}' \
    --tensor-parallel-size 4 \
    --block-size 128 \
    --additional-config '{"online_quant_config": {"global_quant_config": "ptpc_fp8", "exclude_layer": ["lm_head", "model.embed_tokens", "vision_tower", "multi_modal_projector", "patch_merge_mlp", "*block_
sparse_moe"]}}' \
    --language-model-only \
    --speculative-config.method eagle3 \
    --speculative-config.model Inferact/MiniMax-M3-EAGLE3 \
    --speculative-config.num_speculative_tokens 3

lm_eval

lm_eval --model local-completions --model_args model=MiniMaxAI/MiniMax-M3-MXFP8,base_url=http://0.0.0.0:8000/v1/completions,tokenizer_backend=None,tokenized_requests=False,num_concurrent=128,max_retries=10,max_gen_toks=2048,timeout=60000 --batch_size auto --tasks gsm8k --num_fewshot 20

Test Result

lm_eval, EAGLE=3

Tasks	Version	Filter	n-shot	Metric		Value		Stderr
gsm8k	3	flexible-extract	20	exact_match	_	0.9431	_	0.0064
		strict-match	20	exact_match	_	0.9431	_	0.0064

gsm8k: Per-position acceptance rate: 0.876, 0.752, 0.626, Avg Draft acceptance rate: 75.1%

Submission Checklist

• Look over the contributing guidelines at https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.