Copy Testing modules/binaries in Install-Platform (swiftlang#76352)

* Copy Testing modules/binaries in Install-Platform

* Copy full Testing.swiftmodule directory rather than individual files

* Fix Copy-Directory command

Author: jmschonfeld

utils/build.ps1

@@ -2083,6 +2083,19 @@ function Install-Platform([Platform]$Platform, $Arch) {
   }
   Copy-File "$($Arch.XCTestInstallRoot)\usr\lib\swift\$($Platform.ToString().ToLowerInvariant())\$($Arch.LLVMName)\XCTest.swiftmodule" "$XCTestInstallRoot\usr\lib\swift\$($Platform.ToString().ToLowerInvariant())\XCTest.swiftmodule\$($Arch.LLVMTarget).swiftmodule"
   Copy-File "$($Arch.XCTestInstallRoot)\usr\lib\swift\$($Platform.ToString().ToLowerInvariant())\$($Arch.LLVMName)\XCTest.swiftdoc" "$XCTestInstallRoot\usr\lib\swift\$($Platform.ToString().ToLowerInvariant())\XCTest.swiftmodule\$($Arch.LLVMTarget).swiftdoc"
+
+  # Copy Testing
+  $SwiftTestingInstallRoot = [IO.Path]::Combine((Get-InstallDir $HostArch), "Platforms", "${Platform}.platform", "Developer", "Library", "Testing-development")
+  switch ($Platform) {
+    Windows {
+      Copy-File "$($Arch.SwiftTestingInstallRoot)\usr\bin\Testing.dll" "$SwiftTestingInstallRoot\usr\$($Arch.BinaryDir)\"
+      Copy-File "$($Arch.SwiftTestingInstallRoot)\usr\lib\swift\windows\Testing.lib" "$SwiftTestingInstallRoot\usr\lib\swift\windows\$($Arch.LLVMName)\"
+    }
+    default {
+      Copy-File "$($Arch.SwiftTestingInstallRoot)\usr\lib\swift\$($Platform.ToString().ToLowerInvariant())\libTesting.so" "$SwiftTestingInstallRoot\usr\lib\$($Arch.BinaryDir)\"
+    }
+  }
+  Copy-Directory "$($Arch.SwiftTestingInstallRoot)\usr\lib\swift\$($Platform.ToString().ToLowerInvariant())\Testing.swiftmodule" "$SwiftTestingInstallRoot\usr\lib\swift\$($Platform.ToString().ToLowerInvariant())\"
 }
 
 function Build-SQLite($Arch) {