Add add/sub methods that only panic with debug assertions to rustc

[Nilstrieb]

This mitigates the perf impact of enabling overflow checks on rustc. The change to use overflow checks will be done in a later PR.

For rust-lang/compiler-team#724, based on data gathered in #119440.

[rustbot]

r? @wesleywiser

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[Nilstrieb]

@wesleywiser o/

[wesleywiser]

r=me

Could you fix the PR description as well? I don't think #724 is right 😄

[wesleywiser]

@bors rollup=never

Perf sensitive

[Nilstrieb]

I don't think this should be performance sensitive, but you never know what happens
@bors r=wesleywiser

[bors]

📌 Commit 5039160 has been approved by wesleywiser

It is now in the queue for this repository.

[bors]

⌛ Testing commit 5039160 with merge af6a161...

[bors]

☀️ Test successful - checks-actions
Approved by: wesleywiser
Pushing af6a161 to master...

[rust-timer]

Finished benchmarking commit (af6a161): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

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

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)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-3.8%	[-3.8%, -3.8%]	1
All ❌✅ (primary)	-	-	0

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)	1.7%	[1.7%, 1.7%]	1
Regressions ❌ (secondary)	3.0%	[2.0%, 3.6%]	9
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-1.6%	[-1.6%, -1.6%]	1
All ❌✅ (primary)	1.7%	[1.7%, 1.7%]	1

Binary size

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

Bootstrap: 677.445s -> 676.973s (-0.07%)
Artifact size: 315.99 MiB -> 316.12 MiB (0.04%)