Store chunk_domain_size explicitly in Chunk.

[nnethercote]

Currently we compute it on demand, but it's a little simpler and slightly faster to store it.

r? @ghost

[nnethercote]

@bors try @rust-timer queue

[rust-bors]

☀️ Try build successful (CI)
Build commit: f2dee36 (f2dee36bae6b48e996359e187e06284c26c6d3fb, parent: 28c4c7d7abced7b35c49f38149b9cb6ea27dd2a6)

[rust-timer]

Finished benchmarking commit (f2dee36): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking this pull request means it may be perf-sensitive – we'll automatically label it not fit for rolling up. You can override this, but we strongly advise not to, due to possible changes in compiler perf.

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

Instruction count

Our most reliable metric. Used to determine the overall result above. However, even this metric can be noisy.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.9%	[-1.3%, -0.5%]	4
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-0.9%	[-1.3%, -0.5%]	4

Max RSS (memory usage)

Results (secondary 3.9%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	3.9%	[3.9%, 3.9%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Cycles

Results (secondary 2.8%)

A less reliable metric. May be of interest, but not used to determine the overall result above.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	2.8%	[2.8%, 2.8%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Binary size

This benchmark run did not return any relevant results for this metric.

Bootstrap: 474.3s -> 474.199s (-0.02%)
Artifact size: 390.30 MiB -> 390.38 MiB (0.02%)

[cjgillot]

Haha I removed it 2 months ago... #145480