Test indexmap#343 - using hashbrown 0.15 with HashTable

[cuviper]

In indexmap-rs/indexmap#343, I've ported to hashbrown 0.15, which also requires a change from RawTable (now private) to HashTable. This PR is patching to use that unpublished branch so I can test rustc performance.

r? ghost

[cuviper]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 8ed63d7 with merge a560a4e...

[bors]

☀️ Try build successful - checks-actions
Build commit: a560a4e (a560a4ebb62f474a0cad75ba957486c494514e48)

[rust-timer]

Finished benchmarking commit (a560a4e): comparison URL.

Overall result: ✅ improvements - 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
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-0.2%	[-0.2%, -0.2%]	2
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

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

Cycles

Results (secondary -0.9%)

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)	3.2%	[3.2%, 3.2%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.3%	[-2.6%, -2.1%]	3
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 771.847s -> 770.491s (-0.18%)
Artifact size: 341.40 MiB -> 341.34 MiB (-0.02%)

[cuviper]

Looks neutral with a dash of probably-noisy improvement. That's fine!