Use dynamo fake tensor mode in aot_autograd, move aot_autograd compilation to lowering time [Merger of 89672 and 89773] (#90039)
After all of the preparatory commits, this is a subset of the
changes in https://github.com/pytorch/pytorch/pull/89392 that actually
change us to propagating fake tensors to backends.
Signed-off-by: Edward Z. Yang <ezyangfb.com>
This is the merger of Ed's PR #89672, which is a rewrite of an older PR of mine (#89392), with CI Fixes on top of it (#89773)
Pull Request resolved: https://github.com/pytorch/pytorch/pull/90039
Approved by: https://github.com/ezyang
