[perf] Cache the canonical *instantiation* of param-envs (this time but less)

[compiler-errors]

This is horrible

Only do this for enter_canonical.

[compiler-errors]

@bors2 try @rust-timer queue

[rust-bors]

⌛ Trying commit b864867 with merge a585440…

To cancel the try build, run the command @bors2 try cancel.

[rust-bors]

☀️ Try build successful (CI)
Build commit: a585440 (a58544092480ec708b5bef529a02ad6e2b9679d8)

[rust-timer]

Finished benchmarking commit (a585440): comparison URL.

Overall result: ✅ improvements - no action needed

Benchmarking this pull request means it may be perf-sensitive – we'll automatically label it not fit for rolling up. You can override this, but we strongly advise not to, due to possible changes in compiler perf.

@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)	1.0%	[0.9%, 1.0%]	2
Regressions ❌ (secondary)	0.4%	[0.3%, 0.4%]	3
Improvements ✅ (primary)	-0.5%	[-0.9%, -0.1%]	18
Improvements ✅ (secondary)	-3.6%	[-18.9%, -0.1%]	20
All ❌✅ (primary)	-0.4%	[-0.9%, 1.0%]	20

Max RSS (memory usage)

Results (primary 2.8%, secondary -2.9%)

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

	mean	range	count
Regressions ❌ (primary)	2.8%	[1.6%, 5.1%]	3
Regressions ❌ (secondary)	4.3%	[4.3%, 4.3%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-5.3%	[-7.8%, -3.8%]	3
All ❌✅ (primary)	2.8%	[1.6%, 5.1%]	3

Cycles

Results (primary 0.3%, secondary -6.0%)

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

	mean	range	count
Regressions ❌ (primary)	1.8%	[1.3%, 2.3%]	2
Regressions ❌ (secondary)	2.6%	[2.6%, 2.7%]	2
Improvements ✅ (primary)	-2.5%	[-2.5%, -2.5%]	1
Improvements ✅ (secondary)	-10.3%	[-13.2%, -2.4%]	4
All ❌✅ (primary)	0.3%	[-2.5%, 2.3%]	3

Binary size

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

Bootstrap: 755.415s -> 755.104s (-0.04%)
Artifact size: 372.14 MiB -> 372.31 MiB (0.04%)