Refactor Apple target_abi

[madsmtm]

This was bundled together with Arch, which complicated a few code paths and meant we had to do more string matching than necessary.

CC @BlackHoleFox as you've worked on the Apple target spec before

Related: Is there a reason why Target/TargetOptions use StaticCow for so many things, instead of an enum with defined values (and perhaps a catch-all case for custom target json files)? Tagging @Nilstrieb, as you might know?

[rustbot]

r? @lcnr

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[rustbot]

These commits modify compiler targets.
(See the Target Tier Policy.)

[lcnr]

looking through this, pretty certain that this doesn't do any functional changes (so r=me on that front). Unsure whether this split is generally desirable/the state of apple abis more generally

r? compiler

[BlackHoleFox]

Not a t-compiler member but just as someone who works on these files a lot this is an improvement in many ways. Especially the removal of macabi being hardcoded in too many places.

[Noratrieb]

lcnr says there are no functional changes, BlackHoleFox thinks this is an improvement, that sounds good.
@bors r=lcnr,BlackHoleFox

[bors]

📌 Commit 8f0d357 has been approved by lcnr,BlackHoleFox

It is now in the queue for this repository.

[bors]

⌛ Testing commit 8f0d357 with merge 2259028...

[bors]

☀️ Test successful - checks-actions
Approved by: lcnr,BlackHoleFox
Pushing 2259028 to master...

[rust-timer]

Finished benchmarking commit (2259028): comparison URL.

Overall result: no relevant changes - no action needed

@rustbot label: -perf-regression

Instruction count

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

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)	-2.2%	[-2.2%, -2.2%]	1
Improvements ✅ (secondary)	-	-	0
All ❌✅ (primary)	-2.2%	[-2.2%, -2.2%]	1

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: 675.209s -> 673.288s (-0.28%)
Artifact size: 315.95 MiB -> 316.02 MiB (0.02%)