Consider param-env for sizedness fast path

[compiler-errors]

Look up T: Sized in param-env if T is a param or placeholder (the latter is for use in the new solver).

[compiler-errors]

@bors2 try @rust-timer queue

[rust-bors]

⌛ Trying commit 089656e with merge 7c68135…

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

[rust-bors]

☀️ Try build successful (CI)
Build commit: 7c68135 (7c68135aa7729b5e1a168883c992b097f120c51a, parent: 085c24790e591948f788fd294ca3f9858313741c)

[rust-timer]

Finished benchmarking commit (7c68135): 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)	0.3%	[0.3%, 0.3%]	1
Regressions ❌ (secondary)	0.1%	[0.1%, 0.1%]	1
Improvements ✅ (primary)	-0.9%	[-3.6%, -0.1%]	34
Improvements ✅ (secondary)	-1.2%	[-3.0%, -0.3%]	17
All ❌✅ (primary)	-0.9%	[-3.6%, 0.3%]	35

Max RSS (memory usage)

Results (primary -4.0%)

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

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-4.0%	[-4.9%, -1.5%]	9
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-4.0%	[-4.9%, -1.5%]	9

Cycles

Results (primary -1.9%, secondary 2.0%)

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

	mean	range	count
Regressions ❌ (primary)	2.5%	[2.5%, 2.6%]	2
Regressions ❌ (secondary)	2.3%	[0.6%, 4.1%]	11
Improvements ✅ (primary)	-2.9%	[-3.7%, -1.5%]	9
Improvements ✅ (secondary)	-0.8%	[-0.8%, -0.8%]	1
All ❌✅ (primary)	-1.9%	[-3.7%, 2.6%]	11

Binary size

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

Bootstrap: 462.05s -> 462.11s (0.01%)
Artifact size: 372.27 MiB -> 372.22 MiB (-0.01%)

[rustbot]

Some changes occurred to the core trait solver

cc @rust-lang/initiative-trait-system-refactor