Add option to clear metadata in ort fusion (#2685)

Add option to clear metadata in ort fusion. Otherwise, we lose all
metadata after running ORT fusion

---------

Signed-off-by: Ganesan Ramalingam <grama@microsoft.com>

Author: gramalingam

onnxscript/rewriter/ort_fusions/_core.py

@@ -115,6 +115,7 @@ def optimize_for_ort(
     config_name: str | None = None,
     *,
     debug: bool = False,
+    clear_metadata: bool = False,
 ) -> tuple[ir.Model, dict[str, int]]:
     """
     Optimize the model for ORT backend.
@@ -128,6 +129,7 @@ def optimize_for_ort(
             Typically it identifies the Execution Provider (EP) to optimize for.
             If None, the default configuration will be used.
         debug: If debug is True, enable pattern matching tracer for debugging.
+        clear_metadata: If True, clear metadata and doc strings from the model.
 
     Returns:
         A tuple containing:
@@ -145,7 +147,6 @@ def optimize_for_ort(
     passes = ir.passes.Sequential(
         # Apply the ORT optimization passes.
         # https://github.com/microsoft/onnxruntime/blob/74dcf7e296639095dfa55d31336998b6f719ed76/onnxruntime/python/tools/transformers/dynamo_onnx_helper.py#L172
-        common_passes.ClearMetadataAndDocStringPass(),
         # https://github.com/microsoft/onnxruntime/blob/74dcf7e296639095dfa55d31336998b6f719ed76/onnxruntime/python/tools/transformers/dynamo_onnx_helper.py#L139
         common_passes.LiftConstantsToInitializersPass(lift_all_constants=False, size_limit=1),
         common_passes.RemoveInitializersFromInputsPass(),
@@ -154,4 +155,8 @@ def optimize_for_ort(
     assert passes.in_place
     result = passes(model)
     assert result.model is model
+
+    if clear_metadata:
+        common_passes.ClearMetadataAndDocStringPass()(model)
+
     return model, fusion_count