Back out "[nomnigraph][executor] computeChains with nomnigraph" (#15451)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/15451
Original commit changeset: ccd050bfead6
Reviewed By: ilia-cher
Differential Revision: D13533161
fbshipit-source-id: 1d0dcd54c2e3875aab015f3e996693e67a449b87
