Update llama special tokens

Differential Revision: D61730848

Pull Request resolved: #4876

Author: helunwencser

examples/models/llama2/tokenizer/llama_tiktoken.cpp

@@ -23,15 +23,15 @@ _get_default_special_tokens() {
           "<|end_of_text|>",
           "<|reserved_special_token_0|>",
           "<|reserved_special_token_1|>",
-          "<|reserved_special_token_2|>",
-          "<|reserved_special_token_3|>",
+          "<|finetune_right_pad_id|>",
+          "<|step_id|>",
           "<|start_header_id|>",
           "<|end_header_id|>",
-          "<|reserved_special_token_4|>",
-          "<|eot_id|>"});
-
+          "<|eom_id|>",
+          "<|eot_id|>",
+          "<|python_tag|>"});
   // pad the rest of the special tokens with reserved tokens
-  ssize_t reserved_special_token_num = 5;
+  ssize_t reserved_special_token_num = 2;
   while (special_tokens->size() < kSpecialTokensSize) {
     special_tokens->emplace_back(
         "<|reserved_special_token_" +