Remove Zygote rule for *(::AbstractFFTs.Plan, ::AbstractArray)

[vpuri3]

The potentially incorrect Zygote rules for FFT (#899) can be removed now that comprehensive Chain Rules have been added in JuliaMath/AbstractFFTs.jl#67

cc @devmotion

PR Checklist

• [ ] Tests are added
• [ ] Documentation, if applicable

[devmotion]

I assume they can't be removed right now since the AbstractFFT PR is not sufficient - downstream packages have to implement the adjoint functionality first. Otherwise the rules will just error.

[devmotion]

Indeed, tests fail currently since e.g. AbstractFFTs.ProjectionStyle is not defined for FFTW plans.

[piever]

Sorry to just bump this, but I've also run into #899 and wanted to check whether this can be solved. As JuliaMath/FFTW.jl#249 has been merged, would it be possible to tag a patch release of FFTW and merge this?

[vpuri3]

rerunning CI

[vpuri3]

@stevengj, @devmotion could you do this?

Sorry to just bump this, but I've also run into #899 and wanted to check whether this can be solved. As JuliaMath/FFTW.jl#249 has been merged, would it be possible to tag a patch release of FFTW and merge this?

[gaurav-arya]

For tests to pass with this PR, we also need an AbstractFFTs release due to JuliaMath/AbstractFFTs.jl#116. In addition, the (half incorrect) Zygote rules that would be removed here do apply to GPU code, while support for AdjointStyle's by CUDA is bottlenecked by JuliaMath/AbstractFFTs.jl#118.