fix: Repair null bindings issue in TRT Engines (#2080)

Author: gs-olive

py/torch_tensorrt/dynamo/backend/backends.py

@@ -121,6 +121,9 @@ def _compile_module(
         torch_executed_ops=settings.torch_executed_ops,
     )
 
+    # Store TRT replicas of Torch subgraphs
+    trt_modules = {}
+
     # Iterate over all components that can be accelerated
     # Generate the corresponding TRT Module for those
     for name, _ in partitioned_module.named_children():
@@ -138,7 +141,10 @@ def _compile_module(
             settings=settings,
         )
 
-        # Replace FX Module with TRT Module
+        trt_modules[name] = trt_mod
+
+    # Replace all FX Modules with TRT Modules
+    for name, trt_mod in trt_modules.items():
         setattr(partitioned_module, name, trt_mod)
 
     return partitioned_module