C# module benchmarks

[RReverser]

Description of Changes

These are ported from Rust benchmarks 1:1 (similarly to how sdk-test-cs is ported from sdk-test) by using Copilot + elbow grease for manual fixes.

When you set an environment variable STDB_BENCH_CS=1, this allows to run all the same module benchmarks as Rust currently does, except against an analogous C# implementation.

API and ABI breaking changes

If this is an API or ABI breaking change, please apply the
corresponding GitHub label.

Expected complexity level and risk

How complicated do you think these changes are? Grade on a scale from 1 to 5,
where 1 is a trivial change, and 5 is a deep-reaching and complex change.

This complexity rating applies not only to the complexity apparent in the diff,
but also to its interactions with existing and future code.

If you answered more than a 2, explain what is complex about the PR,
and what other components it interacts with in potentially concerning ways.

Testing

Describe any testing you've done, and any testing you'd like your reviewers to do,
so that you're confident that all the changes work as expected!

• Write a test you've completed here. Tried running C# benchmarks.
• Write a test you want a reviewer to do here, so they can check it off when they're satisfied. Try running C# benchmarks.

[RReverser]

Example run in Rust

special/stdb_module/large_arguments/64KiB
                        time:   [75.082 µs 75.849 µs 76.733 µs]
                        change: [-9.7556% -7.9926% -6.4687%] (p = 0.00 < 0.05)
                        Performance has improved.

vs C#

special/stdb_module/large_arguments/64KiB
                        time:   [1.2303 ms 1.2388 ms 1.2474 ms]
                        change: [+1500.6% +1523.1% +1543.4%] (p = 0.00 < 0.05)
                        Performance has regressed.

[RReverser]

For the sake of posterity, here's EXPERIMENTAL_WASM_AOT vs regular C#:

special/stdb_module/large_arguments/64KiB
                        time:   [147.81 µs 149.06 µs 150.45 µs]
                        change: [-86.822% -86.542% -86.228%] (p = 0.00 < 0.05)
                        Performance has improved.
Found 14 outliers among 100 measurements (14.00%)

only 2x slower than Rust (which is in line with my early microbenchmarks).

[cloutiertyler]

This is great to have!

[mamcx]

It was purely to copy the way was done and use the time methods, but is likely that this could be just a const

[mamcx]

LGTM