Fix tests assuming that the temporary directory doesn't include symlinks by @tristanlabelle in https://github.com/apple/swift-corelibs-foundation/pull/4723
Fix typo in doc comment by @valeriyvan in https://github.com/apple/swift-corelibs-foundation/pull/4716
JSONDecoder.readString(): throw on invalid UTF-8 by @ruihe774 in https://github.com/apple/swift-corelibs-foundation/pull/4675
Foundation/Unit: add {m,u,p,n}second units to UnitDuration by @AndrewSB in https://github.com/apple/swift-corelibs-foundation/pull/4708
Use macOS instead of OSX by @AtariDreams in https://github.com/apple/swift-corelibs-foundation/pull/4640
waitUntilExit: ignore RunLoop.run()'s return value by @fischman-bcny in https://github.com/apple/swift-corelibs-foundation/pull/4740
Foundation: implement Bundle.init(for:) on Windows by @compnerd in https://github.com/apple/swift-corelibs-foundation/pull/4744
Move the size check to be the first thing checked in CFAllocator functions by @AtariDreams in https://github.com/apple/swift-corelibs-foundation/pull/4641
Foundation: add some type conversion extensions for Windows by @compnerd in https://github.com/apple/swift-corelibs-foundation/pull/4747
Foundation: support file system representation for long paths by @compnerd in https://github.com/apple/swift-corelibs-foundation/pull/4746
Foundation: simplify handler handling by @compnerd in https://github.com/apple/swift-corelibs-foundation/pull/4751
Tests: correct spelling of /dev/null on Windows by @compnerd in https://github.com/apple/swift-corelibs-foundation/pull/4753
Foundation: correct directory iteration on Windows by @compnerd in https://github.com/apple/swift-corelibs-foundation/pull/4745
Foundation: avoid unnecessary disk IO on windows file enumeration by @compnerd in https://github.com/apple/swift-corelibs-foundation/pull/4748
Windows long paths support by @compnerd in https://github.com/apple/swift-corelibs-foundation/pull/4750
Do not chdir before calling posix_spawn by @Lukasa in https://github.com/apple/swift-corelibs-foundation/pull/4606
Revert "Do not chdir before calling posix_spawn" by @shahmishal in https://github.com/apple/swift-corelibs-foundation/pull/4764
Windows: extend some type conversion definitions by @compnerd in https://github.com/apple/swift-corelibs-foundation/pull/4766
Foundation: support long file paths for FileHandle on Windows by @compnerd in https://github.com/apple/swift-corelibs-foundation/pull/4768
Fix available attributes by @woxtu in https://github.com/apple/swift-corelibs-foundation/pull/4770
Foundation: Windows long file support in FileManager.createDirectory by @compnerd in https://github.com/apple/swift-corelibs-foundation/pull/4771
Foundation: adjust _fileExists for NT style paths by @compnerd in https://github.com/apple/swift-corelibs-foundation/pull/4773
Fix a concurrency bug in the TestFileHandle.test_readToEndOfFileAndNotify() unit test. by @grynspan in https://github.com/apple/swift-corelibs-foundation/pull/4787
Add Sendable to Date, DateComponents and Data by @FranzBusch in https://github.com/apple/swift-corelibs-foundation/pull/4777
Foundation: unmask Windows events on the main RunLoop by @compnerd in https://github.com/apple/swift-corelibs-foundation/pull/4759
Foundation: adjust moveFile to support long paths on Windows by @compnerd in https://github.com/apple/swift-corelibs-foundation/pull/4784
Foundation: use NT-style paths for CopyFileW by @compnerd in https://github.com/apple/swift-corelibs-foundation/pull/4793
Foundation: improve relative path computation for iteration on Windows by @compnerd in https://github.com/apple/swift-corelibs-foundation/pull/4797
Remove an invalid file reference by @woxtu in https://github.com/apple/swift-corelibs-foundation/pull/4796
Fix UserDefaults.string(forKey:) behavior by @woxtu in https://github.com/apple/swift-corelibs-foundation/pull/4780
Fix UserDefaults.integer(forKey:) behavior by @woxtu in https://github.com/apple/swift-corelibs-foundation/pull/4781
Foundation: make _moveItem resilient to multiple volumes by @compnerd in https://github.com/apple/swift-corelibs-foundation/pull/4800
Fix UserDefaults.float(forKey:) behavior by @woxtu in https://github.com/apple/swift-corelibs-foundation/pull/4782
Foundation: adjust _NSCleanupTemporaryFile on Windows by @compnerd in https://github.com/apple/swift-corelibs-foundation/pull/4801
Foundation: alter NSData.contents(of:options:) on Windows by @compnerd in https://github.com/apple/swift-corelibs-foundation/pull/4802
Fix UserDefaults.double(forKey:) behavior by @woxtu in https://github.com/apple/swift-corelibs-foundation/pull/4783
Fix the way known locations are generated on windows by @darinf in https://github.com/apple/swift-corelibs-foundation/pull/4805
Fix JSONDecoder.decode(_,from:) behavior by @ypli-chn in https://github.com/apple/swift-corelibs-foundation/pull/4807
Cherry pick #4827 by @FranzBusch in https://github.com/apple/swift-corelibs-foundation/pull/4829
[5.10] Cherry-pick Fix divergent overwrite behavior of FileManager.copyItem(at:to:) on Linux and Windows by @gwynne in https://github.com/apple/swift-corelibs-foundation/pull/4825
[5.10] Cherry-pick Ensure URLSession and curl agree on the host #4836 by @jrflat in https://github.com/apple/swift-corelibs-foundation/pull/4853
New Contributors
@ruihe774 made their first contribution in https://github.com/apple/swift-corelibs-foundation/pull/4675
@AndrewSB made their first contribution in https://github.com/apple/swift-corelibs-foundation/pull/4708
@fischman-bcny made their first contribution in https://github.com/apple/swift-corelibs-foundation/pull/4740
@darinf made their first contribution in https://github.com/apple/swift-corelibs-foundation/pull/4805
@ypli-chn made their first contribution in https://github.com/apple/swift-corelibs-foundation/pull/4807
Full Changelog: https://github.com/apple/swift-corelibs-foundation/compare/swift-5.9.2-RELEASE...swift-5.10-RELEASE