[Frontend] Add FlexibleArgumentParser to support both underscore and dash in names (#5718)

benchmarks/cutlass_benchmarks/w8a8_benchmarks.py

@@ -11,6 +11,7 @@ from torch.utils.benchmark import Measurement as TMeasurement
 from weight_shapes import WEIGHT_SHAPES
 
 from vllm import _custom_ops as ops
+from vllm.utils import FlexibleArgumentParser
 
 DEFAULT_MODELS = list(WEIGHT_SHAPES.keys())[1:]
 DEFAULT_BATCH_SIZES = [1, 16, 32, 64, 128, 256, 512]
@@ -293,7 +294,7 @@ if __name__ == '__main__':
             return torch.float8_e4m3fn
         raise ValueError("unsupported dtype")
 
-    parser = argparse.ArgumentParser(
+    parser = FlexibleArgumentParser(
         description="""
 Benchmark Cutlass GEMM.