[experimental] Make witnesses more eager

[compiler-errors]

r? lcnr

[compiler-errors]

@bors try @rust-timer queue

[bors]

⌛ Trying commit 7bff9fb with merge aa7f5f1...

[lcnr]

i feel like we prolly want to instead never erase the coroutines, only the defining opaques when creating a TypingEnv from the current infcx

[compiler-errors]

might be expensive to erase on every call to TypingEnv; otherwise i'll keep this and write a comment explaining why it's unsound.

[bors]

☀️ Try build successful - checks-actions
Build commit: aa7f5f1 (aa7f5f1743a191388f6b130b1ea65bcfa321c198)

[rust-timer]

Finished benchmarking commit (aa7f5f1): comparison URL.

Overall result: ✅ improvements - 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 is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-0.2%	[-0.2%, -0.2%]	2
Improvements ✅ (secondary)	-0.4%	[-0.6%, -0.2%]	5
All ❌✅ (primary)	-0.2%	[-0.2%, -0.2%]	2

Max RSS (memory usage)

Results (primary -0.4%, secondary -1.3%)

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)	1.6%	[1.6%, 1.6%]	1
Regressions ❌ (secondary)	0.5%	[0.4%, 0.5%]	3
Improvements ✅ (primary)	-1.4%	[-1.6%, -1.3%]	2
Improvements ✅ (secondary)	-1.6%	[-3.9%, -0.6%]	17
All ❌✅ (primary)	-0.4%	[-1.6%, 1.6%]	3

Cycles

Results (secondary -0.1%)

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)	1.0%	[0.4%, 2.4%]	9
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-1.4%	[-3.7%, -0.5%]	8
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: missing data
Artifact size: 370.26 MiB -> 370.23 MiB (-0.01%)