tokenize : align usage by using common args (#25516)

Migrate the tokenize tool to common_params_parse, replacing its
hand-rolled argv parsing, Windows UTF-8 handling and file reading
with the shared common helpers.

Expose the model-sourcing flags (-m, -mu, -dr, -hf, -hff, --offline,
HF_TOKEN) to LLAMA_EXAMPLE_TOKENIZE, and register --ids, --stdin,
--no-bos, --no-parse-special and --show-count as common args.
parse_special defaults to true for TOKENIZE to preserve the old
behavior. Errors now go through LOG_ERR instead of fprintf(stderr).

Signed-off-by: Adrien Gallouët <angt@huggingface.co>

common/common.h

@@ -105,6 +105,7 @@ enum llama_example {
     LLAMA_EXAMPLE_RESULTS,
     LLAMA_EXAMPLE_EXPORT_GRAPH_OPS,
     LLAMA_EXAMPLE_DOWNLOAD,
+    LLAMA_EXAMPLE_TOKENIZE,
 
     LLAMA_EXAMPLE_COUNT,
 };
@@ -716,6 +717,12 @@ struct common_params {
     // batched-bench params
     bool batched_bench_output_jsonl = false;
 
+    // tokenize params
+    bool tokenize_ids        = false; // if true, only print the token IDs
+    bool tokenize_stdin      = false; // if true, read the prompt from stdin
+    bool tokenize_no_bos     = false; // if true, do not add the BOS token
+    bool tokenize_show_count = false; // if true, print the total token count
+
     // common params
     std::string out_file; // output filename for all example programs
     // optional callback for model loading progress and cancellation: