Regression compiling non-throwing compactMap

[NachoSoto]

Description

The following code compiles fine with Swift 5.x, but Swift 6 produces a bogus diagnostic.

Reproduction

import AppKit

open class Base: NSView {
  override public init(frame: NSRect) {
    super.init(frame: frame)
  }

  @available(*, unavailable)
  public required init?(coder _: NSCoder) {
    fatalError("init(coder:) has not been implemented")
  }
}

final class Subview<View: NSView>: Base {
  var views: [View] {
    let views: [NSView] = []
    // Call can throw, but it is not marked with 'try' and the error is not handled
    return views.compactMap(f)
  }

  private func f(_ view: NSView) -> View? {
    return nil
  }
}

Expected behavior

The code should compile fine, but instead produces

Call can throw, but it is not marked with 'try' and the error is not handled

Environment

swift-driver version: 1.109.2 Apple Swift version 6.0 (swiftlang-6.0.0.3.300 clang-1600.0.20.10)
Target: arm64-apple-macosx14.0

Additional information

I haven't been able to reduce this further without NSView.

[hborla]

I can't reproduce this on main

[NachoSoto]

This is still reproducible with Xcode 16 RC.