Re-enable local std?

[Mark-Simulacrum]

This tracks the potential revert of 048360c, which caused a 10% regression on the collection server.

Before we revert I would like to determine the cause of the regression, i.e., what difference it made that std was built on the collector rather than in Rust's CI. Ideally, that investigation will mean that we adjust Rust's CI to build a better std.

[nnethercote]

Any progress here?

[rylev]

@Mark-Simulacrum what's the latest on this?

[Mark-Simulacrum]

I don't recall doing any further investigation. I'm not sure if it's worth doing that still or if we should just close this.

I'd guess that we could try re-applying that commit ( 048360c) and see whether that gives us a performance win. If so, then exploring how we can adjust rustc mainline CI to get the same win may well be worthwhile.