[experiment] refactor WorkerLocal into enum for parallel compiler

[deltragon]

Based on my suggestion in #109478 (comment).

[rustbot]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @WaffleLapkin (or someone else) soon.

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[deltragon]

@SparrowLii Would it be possible to kick off a perf run for this?

[SparrowLii]

@bors try @rust-timer queue

[bors]

⌛ Trying commit e33599c with merge 0f5c0e5435b325405011cb480748a99a9633e244...

[SparrowLii]

@SparrowLii Would it be possible to kick off a perf run for this?

Yeah sure. Sorry for the missing

[deltragon]

Thanks!

[bors]

☀️ Try build successful - checks-actions
Build commit: 0f5c0e5435b325405011cb480748a99a9633e244 (0f5c0e5435b325405011cb480748a99a9633e244)

[rust-timer]

Finished benchmarking commit (0f5c0e5435b325405011cb480748a99a9633e244): comparison URL.

Overall result: ❌ regressions - no action needed

Benchmarking this pull request likely means that it is perf-sensitive, so we're automatically marking it as not fit for rolling up. While you can manually mark this PR as fit for rollup, we strongly recommend not doing so since this PR may lead to changes in compiler perf.

@bors rollup=never
@rustbot label: -S-waiting-on-perf -perf-regression

Instruction count

This is a highly reliable metric that was used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.3%	[0.3%, 0.3%]	3
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	3.8%	[3.8%, 3.8%]	1
Regressions ❌ (secondary)	1.3%	[0.4%, 3.8%]	9
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.5%	[-0.5%, -0.5%]	1
All ❌✅ (primary)	3.8%	[3.8%, 3.8%]	1

Cycles

Results

This is a less reliable metric that may be of interest but was not used to determine the overall result at the top of this comment.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	0.7%	[0.4%, 1.3%]	6
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.8%	[-1.3%, -0.5%]	3
All ❌✅ (primary)	-	-	0

[SparrowLii]

I think the perf result in #109528 is nice(There is some increase in wall-time, but it has little effect on global effects). Thanks!

[deltragon]

Thank you, for your work on the parallel compiler!