Swift 6 compilation performance regression

[NachoSoto]

Description

The following code now takes over 200ms to type-check (this wasn't an issue with Xcode 16 beta 2):

Expression took 226ms to type-check (limit: 200ms)

Reproduction

@MainActor
public enum Haptics {
  private static let engine: CHHapticEngine? = try? CHHapticEngine()
}

Expected behavior

Type-checks in reasonable time.

Environment

swift-driver version: 1.111.2 Apple Swift version 6.0 (swiftlang-6.0.0.5.15 clang-1600.0.22.6)
Target: arm64-apple-macosx14.0

Additional information

No response

[NachoSoto]

Are you all tracking performance regressions? It's gotten so much worse: https://twitter.com/nachosoto/status/1823115033687310808?s=61&t=SC3rvyJQWn1NQqAgMVrT0Q

[NachoSoto]

This reproduces it too:

let result: CHHapticEngine = try CHHapticEngine(audioSession: nil)

Why would calling a throwing init take so long to type-check?

And this is in Xcode 16 RC.