Nvfuser opt in for decomposition (#81134)
Regarding issues reported in #79246, we notice that bias decomposition from conv/linear could actually hurt perf, due to the overhead of compilation. This PR changes it to make decomposition an explicit opt-in from user to avoid these regressions.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/81134
Approved by: https://github.com/davidberard98
