run-make: annotate library with #[must_use] and enforce unused_must_use in rmake.rs

[jieyouxu]

This PR adds #[must_use] annotations to functions of the run_make_support library where it makes sense, and adjusts compiletest to compile rmake.rs with -Dunused_must_use.

The rationale is that it's highly likely that unused #[must_use] values in rmake.rs test files are bugs. For example, unused fs/io results are often load-bearing to the correctness of the test and often unchecked fs/io results allow the test to silently pass where it would've failed if the result was checked.

This PR is best reviewed commit-by-commit.

try-job: test-various
try-job: x86_64-msvc

[rustbot]

r? @Mark-Simulacrum

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[rustbot]

These commits modify the Cargo.lock file. Unintentional changes to Cargo.lock can be introduced when switching branches and rebasing PRs.

If this was unintentional then you should revert the changes before this PR is merged.
Otherwise, you can ignore this comment.

[jieyouxu]

r? @Kobzol since you also reviewed #125752

[jieyouxu]

@bors try

[bors]

⌛ Trying commit 8d182e3 with merge ef2e85e...

[jieyouxu]

@bors rollup=never (likely conflicts with other rmake.rs PRs)

[bors]

☀️ Try build successful - checks-actions
Build commit: ef2e85e (ef2e85e07ec543371158b7f45fc3e7440450acfd)

[Kobzol]

LGTM, feel free to r=me after #125752 is merged. It might also be good to only merge this after the FS wrapper PR.

[jieyouxu]

@rustbot blocked (on #125752)

[Kobzol]

@rustbot author

[jieyouxu]

I'll try to land this after the fs wrapper PR (#125736), I'll block this PR on the fs wrapper PR and rebase after that and drop the reset-codegen-1 change.

@rustbot blocked (after #125736)

[bors]

☔ The latest upstream changes (presumably #125736) made this pull request unmergeable. Please resolve the merge conflicts.

[jieyouxu]

Unblocked since #125736 is merged. @rustbot author

[jieyouxu]

Rebased and fixed tests, but otherwise no significant changes.

@bors r=@Kobzol rollup=never

[bors]

📌 Commit 5b126ed has been approved by Kobzol

It is now in the queue for this repository.

[jieyouxu]

Oh hm this is going to need another test update if the current rollup passes. EDIT: actually it doesn't

[bors]

⌛ Testing commit 5b126ed with merge 921645c...

[bors]

☀️ Test successful - checks-actions
Approved by: Kobzol
Pushing 921645c to master...

[rust-timer]

Finished benchmarking commit (921645c): comparison URL.

Overall result: ❌ regressions - 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)	2.5%	[2.5%, 2.5%]	1
Improvements ✅ (primary)	-	-	0
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-	-	0

Max RSS (memory usage)

Results (secondary -2.8%)

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)	-2.8%	[-2.8%, -2.8%]	1
All ❌✅ (primary)	-	-	0

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: 668.917s -> 671.475s (0.38%)
Artifact size: 319.72 MiB -> 320.37 MiB (0.20%)

[RalfJung]

This PR contained an odd commit: c8e3eeb didn't change anything. How did that happen?

[Kobzol]

Probably some leftover from a rebase.