Rename arg_iter to iter_instantiated

[compiler-errors]

arg_iter doesn't make sense, and doesn't really indicate what it's doing (returning an iterator that substitutes instantiates its elements).

iter_instantiated_copied is kinda awkward but i don't really wanna bikeshed it.

r? @oli-obk

[rustbot]

Some changes occurred to the core trait solver

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

Some changes occurred in src/tools/clippy

cc @rust-lang/clippy

[oli-obk]

@bors r+

[bors]

📌 Commit 781b1042456e958a3676da69e3bdd36887ffd785 has been approved by oli-obk

It is now in the queue for this repository.

[bors]

☔ The latest upstream changes (presumably #113686) made this pull request unmergeable. Please resolve the merge conflicts.

[compiler-errors]

@bors r=oli-obk

[bors]

📌 Commit 05f6890 has been approved by oli-obk

It is now in the queue for this repository.

[bors]

⌛ Testing commit 05f6890 with merge 6b9236e...

[bors]

☀️ Test successful - checks-actions
Approved by: oli-obk
Pushing 6b9236e to master...

[rust-timer]

Finished benchmarking commit (6b9236e): comparison URL.

Overall result: ✅ improvements - no action needed

@rustbot label: -perf-regression

Instruction count

This is a highly reliable metric that was 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)	-0.6%	[-0.7%, -0.5%]	4
All ❌✅ (primary)	-	-	0

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)	-1.8%	[-2.2%, -1.1%]	4
Improvements ✅ (secondary)	-1.3%	[-1.5%, -1.2%]	2
All ❌✅ (primary)	-1.8%	[-2.2%, -1.1%]	4

Cycles

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

Binary size

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

Bootstrap: 657.921s -> 658.29s (0.06%)