This is a large change because prior to this point, Python files in the
project were not consistently formatted. This reformats them all with
black defaults.
Based on experience with prior projects, if you have a dev/long-term
branch with Python patches, you can minimize merge conflicts prior to
rebasing to include this commit by running `black` on your modified
Python files, squashing, and then rebasing/merging.
This commit adds decomposition support into the core aten operators
before importing the module from torch.
Also, this commit deals with the lifted tensor constants in
torch.export.export(). We don't want to add unnecessary placeholder
nodes in the graph (extra args in the block module), and should treat
them like the constants that they are. The unnecessary clone is also
removed for max efficiency.