Move shape information of RArray to field

[mofeing]

Discussed in #52

@wsmoses Unfortunately, these commits are tangled with the move to the Tracing.jl file.

Changes

• Shape information of an RArray will no longer be contained in a type parameter, but in a field.
• Move tracing-related code to Tracing.jl file.

[wsmoses]

This generally seems reasonable to me -- but would you be able to add the ci for benchmarking so we can test the compile time impact here?

[mofeing]

This might be hard because what needs to be measured is only the compilation time of the first execution.

Also, how should the info be displayed? Just print the timings?

[wsmoses]

@mofeing so it should be fairly easy to do this: https://github.com/EnzymeAD/Enzyme.jl/blob/main/benchmark/benchmarks.jl via https://github.com/EnzymeAD/Enzyme.jl/blob/main/.github/workflows/benchmark_pr.yml

which puts automatically a comment in the PR with the overhead change

[wsmoses]

@mofeing can you rebase this and see if benchmarking runs?

[mofeing]

I'm on it!

[mofeing]

The workflow seems to work but it's BenchmarkTools which is giving me a small headache

[github-actions]

Benchmark Results

	main	6e1c44d...	main/6e1c44df810804...
comptime/basics/2D sum	3.45 s	3.21 s	1.07
comptime/basics/Basic cos	0.19 ± 0.02 s	0.189 ± 0.023 s	1.01
comptime/basics/Basic grad cos	6.85 s	6.61 s	1.04
time_to_load	1.36 ± 0.037 s	1.46 ± 0.011 s	0.933

Benchmark Plots

A plot of the benchmark results have been uploaded as an artifact to the workflow run for this PR.
Go to "Actions"->"Benchmark a pull request"->[the most recent run]->"Artifacts" (at the bottom).

[mofeing]

Finally got it working.

@wsmoses I just added some basic benchmarks. Don't know if you want some more?