add shallow fusion (#147)

sherpa-onnx/csrc/hypothesis.h

@@ -34,13 +34,11 @@ struct Hypothesis {
   // LM log prob if any.
   double lm_log_prob = 0;
 
-  int32_t cur_scored_pos = 0;  // cur scored tokens by RNN LM
+  // the nn lm score for next token given the current ys
+  CopyableOrtValue nn_lm_scores;
+  // the nn lm states
   std::vector<CopyableOrtValue> nn_lm_states;
 
-  // TODO(fangjun): Make it configurable
-  // the minimum of tokens in a chunk for streaming RNN LM
-  int32_t lm_rescore_min_chunk = 2;  // a const
-
   int32_t num_trailing_blanks = 0;
 
   Hypothesis() = default;