Add extra debug assertions for equality for Adt/Variant/FieldDef

[compiler-errors]

Would've made it easier to both catch and test #111494. Maybe not worth it, since it does mean that the compiler is doing extra work when debug-assertions are enabled, but also that's what debug assertions are for :^)

This is a revival of #111523 because I think I pushed an empty branch and bors got a bit too excited it closed the PR.

[rustbot]

r? @lcnr

(rustbot has picked a reviewer for you, use r? to override)

[Noratrieb]

r? Nilstrieb
@bors r+ rollup

[bors]

📌 Commit 2b1d4bf has been approved by Nilstrieb

It is now in the queue for this repository.

[bors]

⌛ Testing commit 2b1d4bf with merge 03761a5...

[bors]

☀️ Test successful - checks-actions
Approved by: Nilstrieb
Pushing 03761a5 to master...

[rust-timer]

Finished benchmarking commit (03761a5): comparison URL.

Overall result: ❌ regressions - no action needed

@rustbot label: -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)	0.5%	[0.5%, 0.5%]	1
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	0.5%	[0.5%, 0.5%]	1

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)	4.4%	[4.4%, 4.4%]	1
Regressions ❌ (secondary)	2.6%	[2.6%, 2.6%]	1
Improvements ✅ (primary)	-3.5%	[-3.5%, -3.5%]	1
Improvements ✅ (secondary)	-2.5%	[-2.5%, -2.5%]	1
All ❌✅ (primary)	0.4%	[-3.5%, 4.4%]	2

Cycles

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

Binary size

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

Bootstrap: 643.76s -> 643.403s (-0.06%)