Add attribute to allow LoggedTest to collect dump on failure (#905)

* Add attribute for collecting dumps for failed LoggedTest

src/Testing/src/CollectDumpAttribute.cs

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+// Copyright(c) .NET Foundation.All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+
+namespace Microsoft.Extensions.Logging.Testing
+{
+    /// <summary>
+    /// Capture the memory dump upon test failure.
+    /// </summary>
+    /// <remarks>
+    /// This currently only works in Windows environments
+    /// </remarks>
+    [AttributeUsage(AttributeTargets.Method, AllowMultiple = false)]
+    public class CollectDumpAttribute : Attribute
+    {
+    }
+}

src/Testing/src/DumpCollector/DumpCollector.Windows.cs

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+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System;
+using System.Diagnostics;
+using System.IO;
+using System.Runtime.InteropServices;
+using Microsoft.Win32.SafeHandles;
+
+namespace Microsoft.Extensions.Logging.Testing
+{
+    public static partial class DumpCollector
+    {
+        private static class Windows
+        {
+            internal static void Collect(Process process, string outputFile)
+            {
+                // Open the file for writing
+                using (var stream = new FileStream(outputFile, FileMode.Create, FileAccess.ReadWrite, FileShare.None))
+                {
+                    // Dump the process!
+                    var exceptionInfo = new NativeMethods.MINIDUMP_EXCEPTION_INFORMATION();
+                    if (!NativeMethods.MiniDumpWriteDump(process.Handle, (uint)process.Id, stream.SafeFileHandle, NativeMethods.MINIDUMP_TYPE.MiniDumpWithFullMemory, ref exceptionInfo, IntPtr.Zero, IntPtr.Zero))
+                    {
+                        var err = Marshal.GetHRForLastWin32Error();
+                        Marshal.ThrowExceptionForHR(err);
+                    }
+                }
+            }
+
+            private static class NativeMethods
+            {
+                [DllImport("Dbghelp.dll")]
+                public static extern bool MiniDumpWriteDump(IntPtr hProcess, uint ProcessId, SafeFileHandle hFile, MINIDUMP_TYPE DumpType, ref MINIDUMP_EXCEPTION_INFORMATION ExceptionParam, IntPtr UserStreamParam, IntPtr CallbackParam);
+
+                [StructLayout(LayoutKind.Sequential, Pack = 4)]
+                public struct MINIDUMP_EXCEPTION_INFORMATION
+                {
+                    public uint ThreadId;
+                    public IntPtr ExceptionPointers;
+                    public int ClientPointers;
+                }
+
+                [Flags]
+                public enum MINIDUMP_TYPE : uint
+                {
+                    MiniDumpNormal = 0,
+                    MiniDumpWithDataSegs = 1 << 0,
+                    MiniDumpWithFullMemory = 1 << 1,
+                    MiniDumpWithHandleData = 1 << 2,
+                    MiniDumpFilterMemory = 1 << 3,
+                    MiniDumpScanMemory = 1 << 4,
+                    MiniDumpWithUnloadedModules = 1 << 5,
+                    MiniDumpWithIndirectlyReferencedMemory = 1 << 6,
+                    MiniDumpFilterModulePaths = 1 << 7,
+                    MiniDumpWithProcessThreadData = 1 << 8,
+                    MiniDumpWithPrivateReadWriteMemory = 1 << 9,
+                    MiniDumpWithoutOptionalData = 1 << 10,
+                    MiniDumpWithFullMemoryInfo = 1 << 11,
+                    MiniDumpWithThreadInfo = 1 << 12,
+                    MiniDumpWithCodeSegs = 1 << 13,
+                    MiniDumpWithoutAuxiliaryState = 1 << 14,
+                    MiniDumpWithFullAuxiliaryState = 1 << 15,
+                    MiniDumpWithPrivateWriteCopyMemory = 1 << 16,
+                    MiniDumpIgnoreInaccessibleMemory = 1 << 17,
+                    MiniDumpWithTokenInformation = 1 << 18,
+                    MiniDumpWithModuleHeaders = 1 << 19,
+                    MiniDumpFilterTriage = 1 << 20,
+                    MiniDumpWithAvxXStateContext = 1 << 21,
+                    MiniDumpWithIptTrace = 1 << 22,
+                    MiniDumpValidTypeFlags = (-1) ^ ((~1) << 22)
+                }
+            }
+        }
+    }
+}

src/Testing/src/DumpCollector/DumpCollector.cs

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+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+using System.Diagnostics;
+using System.Runtime.InteropServices;
+
+namespace Microsoft.Extensions.Logging.Testing
+{
+    public static partial class DumpCollector
+    {
+        public static void Collect(Process process, string fileName)
+        {
+            if (RuntimeInformation.IsOSPlatform(OSPlatform.Windows))
+            {
+                Windows.Collect(process, fileName);
+            }
+            // No implementations yet for macOS and Linux
+        }
+    }
+}