(ci) Update macOS Xcode to 15

[ehuss]

This updates the macOS builders to Xcode 15. The aarch64 images will be removing Xcode 14 and 16 very soon (actions/runner-images#10703), so we will need to make the switch to continue operating. The linked issue also documents GitHub's new policy for how they will be updating Xcode in the future. Also worth being aware of is the future plans for x86 runners documented in actions/runner-images#9255 and actions/runner-images#10686, which will impact our future upgrade behaviors.

I decided to also update the Xcode in the x86_64 runners, even though they are not being removed. It felt better to me to have all macOS runners on the same (major) version of Xcode. However, note that the x86_64 runners do not have the latest version of 15 (15.4), so I left them at 15.2 (which is currently the default Xcode of the runner).

Xcode 15 was previously causing problems (see #121058) which seem to be resolved now. @bjorn3 fixed the invalid r_symbolnum issue with cranelift. The issue with clang failing to link seems to be fixed, possibly by the update of the pre-built LLVM from 14 to llvm 15 in #124850, or an update in our source version of LLVM. I have run some try builds and at least LLVM seems to build (I did not run any tests).

Closes #121058

[rustbot]

r? @Mark-Simulacrum

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[Mark-Simulacrum]

@bors r+ rollup=never

[bors]

📌 Commit 94579ff has been approved by Mark-Simulacrum

It is now in the queue for this repository.

[bors]

⌛ Testing commit 94579ff with merge 437be25...

[bors]

💔 Test failed - checks-actions

[jieyouxu]

2024-10-16T23:29:32.9094290Z failures:
2024-10-16T23:29:32.9095000Z     [debuginfo-lldb] tests/debuginfo/constant-ordering-prologue.rs

@bors r-

[bjorn3]

@bors r-

Bors got confused.

[ehuss]

I updated the test due to a small change in how lldb displays values in the newer xcode.

@bors r=Mark-Simulacrum

[bors]

📌 Commit 16b91e8 has been approved by Mark-Simulacrum

It is now in the queue for this repository.

[bors]

⌛ Testing commit 16b91e8 with merge 4392847...

[bors]

☀️ Test successful - checks-actions
Approved by: Mark-Simulacrum
Pushing 4392847 to master...

[rust-timer]

Finished benchmarking commit (4392847): comparison URL.

Overall result: ✅ improvements - no action needed

@rustbot label: -perf-regression

Instruction count

This is the most reliable metric that we have; it was used to determine the overall result at the top of this comment. However, even this metric can sometimes exhibit noise.

	mean	range	count
Regressions ❌ (primary)	-	-	0
Regressions ❌ (secondary)	-	-	0
Improvements ✅ (primary)	-3.6%	[-3.6%, -3.6%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-3.6%	[-3.6%, -3.6%]	1

Max RSS (memory usage)

Results (primary -2.3%, secondary -1.9%)

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)	-2.3%	[-2.3%, -2.3%]	1
Improvements ✅ (secondary)	-1.9%	[-2.8%, -1.1%]	2
All ❌✅ (primary)	-2.3%	[-2.3%, -2.3%]	1

Cycles

Results (primary -3.9%)

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)	-3.9%	[-3.9%, -3.9%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-3.9%	[-3.9%, -3.9%]	1

Binary size

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

Bootstrap: 782.781s -> 780.876s (-0.24%)
Artifact size: 333.65 MiB -> 333.66 MiB (0.00%)

[cuviper]

Looks like this is necessary on beta as well, so I'm unilaterally backporting it.
(Xcode 14 failed in #133077 (comment))

@rustbot label +beta-accepted