Kernel fusion for Llama-v2

[TejaGollapudi]

Hi,
https://twitter.com/pommedeterre33/status/1681935636129873920?t=VaxYpkbwNLKxly7icie8kw&s=19

I came across this great thread showing the benefits of kernel fusion for speeding up LLama-2 up to 1.8x using OpenAI's Triton kernels. (It may work with torch kernel fusions too).

Not sure if this would be beneficial for vLLM but it might be worth taking a look at 😄