Refactor `truncate_long_and_double` in Dynamo

[gs-olive]

• Explicit considerations of truncation of inputs versus truncation of constants

Sourced from #2457 (comment):

• Avoid running PyTorch graphs with invalid casts
• Refactor repair_long_and_double to consume output of type inference
• Reorder truncation to come as late as possible in the compilation process

[gs-olive]

Fix the following validator, which uses torch input types pre-truncation:

TensorRT/py/torch_tensorrt/dynamo/conversion/aten_ops_converters.py

Lines 400 to 401 in 4b608f0

	if val is not None and val.dtype != torch.int32:
	return False