Fix guided sampling with outlines

[tae-su-kim]

Current habana_main and habana_next includes guided decoding related code from vllm, and the feature is already there in the openAI api endpoint. However, guided decoding currently fails to run with following error:

  File "/usr/local/lib/python3.10/dist-packages/torch/nn/modules/module.py", line 1564, in _call_impl
    result = forward_call(*args, **kwargs)
  File "/workspace/codes/vllm/model_executor/layers/sampler.py", line 98, in forward
    sample_results, maybe_sampled_tokens_tensor = _sample(
  File "/workspace/codes/vllm/model_executor/layers/sampler.py", line 674, in _sample
    return _sample_with_torch(
  File "/workspace/codes/vllm/model_executor/layers/sampler.py", line 561, in _sample_with_torch
    sample_results = _greedy_sample(seq_groups, greedy_samples, token_positions_only)
  File "/workspace/codes/vllm/model_executor/layers/sampler.py", line 306, in _greedy_sample
    samples = samples.tolist()
RuntimeError: synNodeCreateWithId failed for node: strided_insert with synStatus 1 [Invalid argument]. .

This PR suggests to use masked_fill rather than _add for the masking process of guided decode. With this PR, openai endpoint supports guided decoding. For example:

Input:

payload = {
        "model": "/models/Meta-Llama-3-8B-Instruct",
        "messages": [
            {"role": "user", "content": "reply negatively."}
        ],
        "best_of": best_of,
        "use_beam_search": use_beam_search,
        "temperature": 0.0,
        "top_p": 1.0,
        "guided_regex": "[Pp]ositive format |[Nn]egative format",
}

Output:

{'id': 'cmpl-f3e792eb0197492a8d7eec4bb9916936', 'object': 'chat.completion', 'created': 1722847036, 'model': '/models/Meta-Llama-3-8B-Instruct', 'choices': [{'index': 0, 'message': {'role': 'assistant', 'content': 'Negative format'}, 'logprobs': None, 'finish_reason': 'stop', 'stop_reason': None}], 'usage': {'prompt_tokens': 14, 'total_tokens': 21, 'completion_tokens': 7}}

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[tae-su-kim]

I am closing this PR since habana_next is deprecated. Rebase to habana_main is here: PR #226.