Compilation errors in `trtllm_allreduce_fusion.cuh: undefined AllReduceFusionPattern enum and std::optional`

[b8zhong]

We saw failure on H20 in SGLang for trtllm_allreduce_fusion. Weird, because it's the same CC as H100/H200, where it works fine.

Seems to be some compilation issue? Unfortunately, I don't have an H20 machine to test this with.

https://github.com/sgl-project/sglang/actions/runs/20109255725/job/57739940169?pr=14764

[yzh119]

is there any g++/gcc version difference?