Implement clone_from for BorrowckDomain

[TaKO8Ki]

I've added a similar implementation for BorrowckDomain as for rustc_const_eval::check_consts::resolver::State.

rust/compiler/rustc_const_eval/src/check_consts/resolver.rs

Lines 270 to 281 in 208a58d

	impl Clone for State {
	fn clone(&self) -> Self {
	State { qualif: self.qualif.clone(), borrow: self.borrow.clone() }
	}
	// Data flow engine when possible uses `clone_from` for domain values.
	// Providing an implementation will avoid some intermediate memory allocations.
	fn clone_from(&mut self, other: &Self) {
	self.qualif.clone_from(&other.qualif);
	self.borrow.clone_from(&other.borrow);
	}
	}

[TaKO8Ki]

@bors try @rust-timer queue

[rust-bors]

☀️ Try build successful (CI)
Build commit: f776b65 (f776b65df91f16f1ee06fb6deba9f1aea2f35ee5)
Base parent: 5ec56e3 (5ec56e3902656f2460259fc3ac0f6e2255f94417)

[rust-timer]

Finished benchmarking commit (f776b65): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking means the PR may be perf-sensitive. It's automatically marked not fit for rolling up. Overriding is possible but disadvised: it risks changing compiler perf.

@bors rollup=never rustc-perf
@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)	-0.2%	[-0.3%, -0.1%]	17
Improvements ✅ (secondary)	-0.2%	[-0.3%, -0.1%]	13
All ❌✅ (primary)	-0.2%	[-0.3%, -0.1%]	17

Max RSS (memory usage)

Results (primary -2.6%, secondary 0.1%)

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)	4.4%	[4.4%, 4.4%]	1
Improvements ✅ (primary)	-2.6%	[-2.6%, -2.6%]	1
Improvements ✅ (secondary)	-4.1%	[-4.1%, -4.1%]	1
All ❌✅ (primary)	-2.6%	[-2.6%, -2.6%]	1

Cycles

Results (primary 0.7%, secondary 4.5%)

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

	mean	range	count
Regressions ❌ (primary)	2.6%	[2.6%, 2.6%]	2
Regressions ❌ (secondary)	4.5%	[4.5%, 4.5%]	1
Improvements ✅ (primary)	-3.2%	[-3.2%, -3.2%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.7%	[-3.2%, 2.6%]	3

Binary size

This perf run didn't have relevant results for this metric.

Bootstrap: 487.044s -> 488.946s (0.39%)
Artifact size: 406.45 MiB -> 406.61 MiB (0.04%)

[rustbot]

r? @mati865

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They will have a look at your PR within the next two weeks and either review your PR or reassign to another reviewer.

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The reviewer was selected based on:

• Owners of files modified in this PR: borrowck, compiler
• borrowck, compiler expanded to 77 candidates
• Random selection from 20 candidates