Improve ProcessManager.Win (dotnet#32010)

* ---- Style changes start here ----

* Remove unnecessary using directives

* Remove unnecessary assignments

* Use IntPtr.Zero

* Replace magic numbers

* Remove unused parameters

* Replace constructor with initializer

* Simplify delegate interop

* Inline temporary variables

* Remove unnecessary checked keyword

* Remove unnecessary cast

* Introduce using statement

* ---- Style changes end here ----

* Remove magic sleep

* Prealloc list

* Reduce copying

* Use ArrayPool

* Support long path

* Improve P/Invoke signatures

* Optimize modules enumeration

* Rename and move HandleLastWin32Error

* while (true)

* Move comments near codes

* Revert "Support long path"

This reverts commit 1f06435.

* Revert "Introduce using statement"

This reverts commit e3d383a.

* Revert "Remove magic sleep"

This reverts commit d8bc001.

* Add braces

* Simplify initialization

* Fix last Win32 error

* Avoid reallocation if modules count decreased

* Nits

* Simplify codes

src/libraries/Common/src/Interop/Windows/Kernel32/Interop.EnumProcessModules.cs

@@ -11,6 +11,6 @@ internal partial class Interop
     internal partial class Kernel32
     {
         [DllImport(Libraries.Kernel32, CharSet = CharSet.Unicode, SetLastError = true, EntryPoint = "K32EnumProcessModules")]
-        internal static extern bool EnumProcessModules(SafeProcessHandle handle, IntPtr modules, int size, ref int needed);
+        internal static extern bool EnumProcessModules(SafeProcessHandle handle, IntPtr[]? modules, int size, out int needed);
     }
 }

src/libraries/Common/src/Interop/Windows/Kernel32/Interop.IsWow64Process_SafeProcessHandle.cs

@@ -10,6 +10,6 @@ internal partial class Interop
     internal partial class Kernel32
     {
         [DllImport(Libraries.Kernel32, SetLastError = true)]
-        internal static extern bool IsWow64Process(SafeProcessHandle hProcess, ref bool Wow64Process);
+        internal static extern bool IsWow64Process(SafeProcessHandle hProcess, out bool Wow64Process);
     }
 }

src/libraries/System.Diagnostics.Process/src/System/Diagnostics/ProcessInfo.cs

@@ -3,7 +3,6 @@
 // See the LICENSE file in the project root for more information.
 
 using System.Collections.Generic;
-using System.ComponentModel;
 
 namespace System.Diagnostics
 {
@@ -15,9 +14,9 @@ namespace System.Diagnostics
     /// </summary>
     internal sealed class ProcessInfo
     {
-        internal readonly List<ThreadInfo> _threadInfoList = new List<ThreadInfo>();
+        internal readonly List<ThreadInfo> _threadInfoList;
         internal int BasePriority { get; set; }
-        internal string ProcessName { get; set; }
+        internal string ProcessName { get; set; } = string.Empty;
         internal int ProcessId { get; set; }
         internal long PoolPagedBytes { get; set; }
         internal long PoolNonPagedBytes { get; set; }
@@ -33,20 +32,12 @@ internal sealed class ProcessInfo
 
         internal ProcessInfo()
         {
-            BasePriority = 0;
-            ProcessName = "";
-            ProcessId = 0;
-            PoolPagedBytes = 0;
-            PoolNonPagedBytes = 0;
-            VirtualBytes = 0;
-            VirtualBytesPeak = 0;
-            WorkingSet = 0;
-            WorkingSetPeak = 0;
-            PageFileBytes = 0;
-            PageFileBytesPeak = 0;
-            PrivateBytes = 0;
-            SessionId = 0;
-            HandleCount = 0;
+            _threadInfoList = new List<ThreadInfo>();
+        }
+
+        internal ProcessInfo(int threadsNumber)
+        {
+            _threadInfoList = new List<ThreadInfo>(threadsNumber);
         }
     }
 }