Remove all the rule overload generation stuff

[oxinabox]

We are moving all this stuff into its own package
Requires JuliaDiff/ChainRulesOverloadGeneration.jl#1 to be merged and a relase tagged first so that the docs don't hit a page in those docs that doesn't exist.

This will close #340

It will break invenia/Nabla.jl#189
I don't think it will break any code in the wild.
So we could perhaps do this as a nonbreaking release.
Otherwise: we can merge this once we are ready to tag a breaking release.
Probably in the interests of responsibility we should do that.

I don't think this is worth deprecating, because working out how to do that without a circular dependency seems hard.

Waiting for JuliaRegistries/General#37582

[codecov-commenter]

Codecov Report

Merging #356 (b70ead7) into master (7510c4f) will decrease coverage by 0.88%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master     #356      +/-   ##
==========================================
- Coverage   86.71%   85.82%   -0.89%     
==========================================
  Files          14       13       -1     
  Lines         542      494      -48     
==========================================
- Hits          470      424      -46     
+ Misses         72       70       -2     

Impacted Files	Coverage Δ
src/ChainRulesCore.jl	100.00% <ø> (ø)

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[oxinabox]

This doesn't seem to have much decrease on load time for me.
But also mu load times are for some reason much much higher than @simeonschaub reported in #341

Current Master

(ChainRulesCore) pkg> precompile

julia> @time using ChainRulesCore
  0.833778 seconds (1.45 M allocations: 82.013 MiB, 1.14% gc time)

This PR

Precompiling project...
  1 dependency successfully precompiled in 2 seconds (4 already precompiled)

julia> @time using ChainRulesCore
  0.796725 seconds (1.33 M allocations: 74.891 MiB, 2.00% gc time)

my system

julia> versioninfo()
Julia Version 1.6.2-pre.0
Commit dd122918ce* (2021-04-23 21:21 UTC)
Platform Info:
  OS: macOS (x86_64-apple-darwin20.3.0)
  CPU: Intel(R) Core(TM) i7-8559U CPU @ 2.70GHz
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-11.0.1 (ORCJIT, skylake)

[simeonschaub]

Sorry, I just got my new laptop and was having some issues with my setup, so it took me a bit longer to respond.

ChainRulesCore#master:

julia> @time using ChainRulesCore
  0.129288 seconds (183.98 k allocations: 11.294 MiB, 7.01% compilation time)

ChainRulesCore#ox/nogen:

julia> @time using ChainRulesCore
  0.033548 seconds (50.97 k allocations: 3.213 MiB, 11.55% compilation time)

🎉

julia> versioninfo()
Julia Version 1.7.0-DEV.1170
Commit d0a6b3a814 (2021-05-26 19:20 UTC)
Platform Info:
  OS: Linux (x86_64-pc-linux-gnu)
  CPU: AMD Ryzen 7 PRO 4750U with Radeon Graphics
  WORD_SIZE: 64
  LIBM: libopenlibm
  LLVM: libLLVM-12.0.0 (ORCJIT, znver2)

[oxinabox]

Cool, I will have to workout why things are so slow for me, but that is a question for another day

[simeonschaub]

I think @IanButterworth did some experiments a while back and figured out that sometimes I/O can be unusually slow on Darwin. Could definitely be wrong about this though.

[simeonschaub]

LGTM!

[IanButterworth]

some experiments a while back and figured out that sometimes I/O can be unusually slow on Darwin.

I don't know if it explains all of the slowness on MacOS generally, but yeah, particularly JuliaLang/julia#35907 (comment) which MacOS devs confirmed was to be expected because MacOS does more things during IO

[mzgubic]

Are we ready to merge this with #358? And then tag a breaking release?

[oxinabox]

Are we ready to merge this with #358? And then tag a breaking release?

We can't merge this til JuliaRegistries/General#37582 or there will be a broken link in docs.
we also should check all out downstreams are upgraded to not use deprecations so the update can be smooth.
So lets do this on Monday.