rustdoc: migrate item_typedef to an Askama template

[notriddle]

Part of #108868

[rustbot]

r? @jsha

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[bors]

☔ The latest upstream changes (presumably #110666) made this pull request unmergeable. Please resolve the merge conflicts.

[bors]

☔ The latest upstream changes (presumably #111001) made this pull request unmergeable. Please resolve the merge conflicts.

[GuillaumeGomez]

I'm really not a big fan of using more templating in cases as small as this one: it increases code complexity quite a lot. Let's check the perf result to see if we have gains though.

@bors try @rust-timer queue

[bors]

⌛ Trying commit 786311c with merge 796eb677726e5d6ac08a7ab1b1d49e8f0449f110...

[bors]

☀️ Try build successful - checks-actions
Build commit: 796eb677726e5d6ac08a7ab1b1d49e8f0449f110 (796eb677726e5d6ac08a7ab1b1d49e8f0449f110)

[rust-timer]

Finished benchmarking commit (796eb677726e5d6ac08a7ab1b1d49e8f0449f110): comparison URL.

Overall result: no relevant changes - 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 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)	-1.1%	[-1.1%, -1.1%]	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)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-2.5%	[-2.8%, -2.3%]	2
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 658.519s -> 659.197s (0.10%)

[GuillaumeGomez]

There doesn't seem to be any gain from this. So what do you want to do @notriddle?