xtts: allow loading custom autoregressive model

TTS/tts/models/xtts.py

@@ -767,6 +767,7 @@ class Xtts(BaseTTS):
         eval=True,
         strict=True,
         use_deepspeed=False,
+        autoregressive_model_path=None,
     ):
         """
         Loads a checkpoint from disk and initializes the model's state and tokenizer.
@@ -798,6 +799,9 @@ class Xtts(BaseTTS):
         for key in list(checkpoint.keys()):
             if key.split(".")[0] in ignore_keys:
                 del checkpoint[key]
+        if autoregressive_model_path is not None:
+            checkpoint["gpt"] = torch.load(autoregressive_model_path, map_location=torch.device("cpu"))
+
         self.load_state_dict(checkpoint, strict=strict)
 
         if eval: