Imported Upstream version 6.0.0.172

Former-commit-id: f3cc9b82f3e5bd8f0fd3ebc098f789556b44e9cd

mcs/class/corlib/System.IO.Enumeration/FileSystemEntry.NotSupported.cs

@@ -0,0 +1,15 @@
+using System.Collections;
+
+namespace System.IO.Enumeration
+{
+	public unsafe ref partial struct FileSystemEntry
+	{
+		public ReadOnlySpan<char> Directory { get => throw new PlatformNotSupportedException (); }
+		public ReadOnlySpan<char> RootDirectory { get => throw new PlatformNotSupportedException (); }
+		public ReadOnlySpan<char> OriginalRootDirectory { get => throw new PlatformNotSupportedException (); }
+		public ReadOnlySpan<char> FileName { get => throw new PlatformNotSupportedException (); }
+		public bool IsDirectory => throw new PlatformNotSupportedException ();
+		public FileSystemInfo ToFileSystemInfo() => throw new PlatformNotSupportedException ();
+
+	}
+}

mcs/class/corlib/System.IO.Enumeration/FileSystemEnumerator.NotSupported.cs

@@ -0,0 +1,23 @@
+using System.Collections;
+
+namespace System.IO.Enumeration
+{
+	partial class FileSystemEnumerator<TResult>
+	{
+		public FileSystemEnumerator(string directory, EnumerationOptions options = null) { }
+		bool IEnumerator.MoveNext() => throw new PlatformNotSupportedException ();
+		private string _currentPath = null;
+		private TResult _current = default;
+#pragma warning disable 414
+		private ICollection _pending = null;
+		private bool _lastEntryFound = false;
+		private int _entry = 0;
+#pragma warning restore 414
+
+		private void CloseDirectoryHandle() => throw new PlatformNotSupportedException ();
+		private bool DequeueNextDirectory() => throw new PlatformNotSupportedException ();
+		private unsafe void FindNextEntry() => throw new PlatformNotSupportedException ();
+		private void InternalDispose(bool disposing) { }
+
+	}
+}