Convert Into<ExitStatus> for ExitStatusError to From<ExitStatusError> for ExitStatus in std::process

[ChaiTRex]

Implementing suggestion from #84908 (comment):

I believe the impl on ExitStatusError should be

impl From<ExitStatusError> for ExitStatus

rather than

impl Into<ExitStatus> for ExitStatusError

(there is generally never anything implemented as Into first, because implementing From reflexively provides Into)

[rustbot]

r? @thomcc

(rustbot has picked a reviewer for you, use r? to override)

[thomcc]

This needs libs-api FCP, and possibly ACP.

r? libs-api

[thomcc]

Rerolling because @BurntSushi doesn't review libs PRs (we should get a better system for this).

r? libs-api

[dtolnay]

Thanks!

ExitStatusError is unstable (#84908) so there should be no difference here to stable surface area of the standard library — I don't think an FCP is needed.

[dtolnay]

@bors r+

[bors]

📌 Commit 6acb415 has been approved by dtolnay

It is now in the queue for this repository.

[bors]

⌛ Testing commit 6acb415 with merge c01d8d2...

[bors]

☀️ Test successful - checks-actions
Approved by: dtolnay
Pushing c01d8d2 to master...

[rust-timer]

Finished benchmarking commit (c01d8d2): 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)	-0.3%	[-0.3%, -0.3%]	3
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)	3.3%	[3.3%, 3.3%]	1
Regressions ❌ (secondary)	2.9%	[2.9%, 2.9%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	3.3%	[3.3%, 3.3%]	1

Cycles

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)	-	-	0
Improvements ✅ (secondary)	-4.7%	[-5.5%, -2.2%]	7
All ❌✅ (primary)	-	-	0

Binary size

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

Bootstrap: 630.726s -> 630.425s (-0.05%)
Artifact size: 317.32 MiB -> 317.28 MiB (-0.01%)