[perf-only] rustdoc: Unconditionally enable --generate-link-to-definition and eagerly typeck nested bodies

[fmease]

Compare with: #156355, #156348.

[fmease]

@bors try parent=fb0a5a5a9c892b351f34263d6d84da9dde72871a @rust-timer queue

[fmease]

Lol, not cfg'ed out, I misunderstood. We're obv now typeck'ing bodies which we're usually not doing in rustdoc which means we can't document std anymore.

View changes since the review

[rust-bors]

☀️ Try build successful (CI)
Build commit: ea5e0a8 (ea5e0a8bc1ea61d698cc6ce2eb2169148cee0c18, parent: fb0a5a5a9c892b351f34263d6d84da9dde72871a)

[rust-timer]

Finished benchmarking commit (ea5e0a8): comparison URL.

Overall result: ❌ regressions - please read:

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.

Next, please: If you can, justify the regressions found in this try perf run in writing along with @rustbot label: +perf-regression-triaged. If not, fix the regressions and do another perf run. Neutral or positive results will clear the label automatically.

@bors rollup=never
@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)	21.2%	[3.7%, 50.7%]	19
Regressions ❌ (secondary)	16.0%	[0.3%, 126.7%]	22
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	21.2%	[3.7%, 50.7%]	19

Max RSS (memory usage)

Results (primary 5.9%, secondary 4.8%)

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

	mean	range	count
Regressions ❌ (primary)	6.4%	[1.0%, 17.4%]	17
Regressions ❌ (secondary)	4.8%	[2.0%, 10.8%]	10
Improvements ✅ (primary)	-1.9%	[-1.9%, -1.9%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	5.9%	[-1.9%, 17.4%]	18

Cycles

Results (primary 27.0%, secondary 16.0%)

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

	mean	range	count
Regressions ❌ (primary)	27.0%	[3.9%, 63.1%]	19
Regressions ❌ (secondary)	16.0%	[2.2%, 112.7%]	21
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	27.0%	[3.9%, 63.1%]	19

Binary size

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

Bootstrap: 497.93s -> 499.015s (0.22%)
Artifact size: 397.14 MiB -> 397.09 MiB (-0.01%)