Create JSON from new FX IR and lower to LLVM (#77765)
Summary:
Replace TensorView objects with maps for JSONing.
Lower to LLVM.
Reviewed By: jaybean-dev, jfix71
Differential Revision: D36318989
Pull Request resolved: https://github.com/pytorch/pytorch/pull/77765
Approved by: https://github.com/jfix71, https://github.com/jamesr66a
