Enable IDE0040: AddAccessibilityModifiers (#13962)

https://docs.microsoft.com/dotnet/fundamentals/code-analysis/style-rules/ide0040

.globalconfig

@@ -845,7 +845,7 @@ dotnet_diagnostic.IDE0038.severity = silent
 dotnet_diagnostic.IDE0039.severity = silent
 
 # IDE0040: AddAccessibilityModifiers
-dotnet_diagnostic.IDE0040.severity = silent
+dotnet_diagnostic.IDE0040.severity = warning
 
 # IDE0041: UseIsNullCheck
 dotnet_diagnostic.IDE0041.severity = silent

src/System.Management.Automation/engine/PSConfiguration.cs

@@ -290,12 +290,12 @@ namespace System.Management.Automation.Configuration
         /// <summary>
         /// The supported separator characters for listing channels and keywords in configuration.
         /// </summary>
-        static readonly char[] s_valueSeparators = new char[] {' ', ',', '|'};
+        private static readonly char[] s_valueSeparators = new char[] {' ', ',', '|'};
 
         /// <summary>
         /// Provides a string name to indicate the default for a configuration setting.
         /// </summary>
-        const string LogDefaultValue = "default";
+        private const string LogDefaultValue = "default";
 
         /// <summary>
         /// Gets the bitmask of the PSChannel values to log.

src/System.Management.Automation/utils/tracing/SysLogProvider.cs

@@ -80,11 +80,12 @@ namespace System.Management.Automation.Tracing
     internal class SysLogProvider
     {
         // Ensure the string pointer is not garbage collected.
-        static IntPtr _nativeSyslogIdent = IntPtr.Zero;
-        static readonly NativeMethods.SysLogPriority _facility = NativeMethods.SysLogPriority.Local0;
-        readonly byte _channelFilter;
-        readonly ulong _keywordFilter;
-        readonly byte _levelFilter;
+        private static IntPtr _nativeSyslogIdent = IntPtr.Zero;
+        private static readonly NativeMethods.SysLogPriority _facility = NativeMethods.SysLogPriority.Local0;
+
+        private readonly byte _channelFilter;
+        private readonly ulong _keywordFilter;
+        private readonly byte _levelFilter;
 
         /// <summary>
         /// Initializes a new instance of this class.
@@ -147,7 +148,7 @@ namespace System.Management.Automation.Tracing
         /// to ensure correct thread initialization.
         /// </remarks>
         [ThreadStatic]
-        static Guid? t_activity;
+        private static Guid? t_activity;
 
         private static Guid Activity
         {
@@ -275,7 +276,7 @@ namespace System.Management.Automation.Tracing
 #region logging
 
         // maps a LogLevel to an associated SysLogPriority.
-        static readonly NativeMethods.SysLogPriority[] _levels =
+        private static readonly NativeMethods.SysLogPriority[] _levels =
         {
             NativeMethods.SysLogPriority.Info,
             NativeMethods.SysLogPriority.Critical,
@@ -374,7 +375,7 @@ namespace System.Management.Automation.Tracing
 
     internal static class NativeMethods
     {
-        const string libpslnative = "libpsl-native";
+        private const string libpslnative = "libpsl-native";
         /// <summary>
         /// Write a message to the system logger, which in turn writes the message to the system console, log files, etc.
         /// See man 3 syslog for more info.

test/tools/TestExe/TestExe.cs

@@ -7,9 +7,9 @@ using System.Diagnostics;
 
 namespace TestExe
 {
-    class TestExe
+    internal class TestExe
     {
-        static int Main(string[] args)
+        private static int Main(string[] args)
         {
             if (args.Length > 0)
             {
@@ -44,7 +44,7 @@ namespace TestExe
         // <Summary>
         // Echos back to stdout the arguments passed in
         // </Summary>
-        static void EchoArgs(string[] args)
+        private static void EchoArgs(string[] args)
         {
             for (int i = 1; i < args.Length; i++)
             {
@@ -56,7 +56,7 @@ namespace TestExe
         // First argument is the number of child processes to create which are instances of itself
         // Processes automatically exit after 100 seconds
         // </Summary>
-        static void CreateChildProcess(string[] args)
+        private static void CreateChildProcess(string[] args)
         {
             if (args.Length > 1)
             {

test/tools/TestService/Program.cs

@@ -5,9 +5,9 @@ using System.ServiceProcess;
 
 namespace TestService
 {
-    static class Program
+    internal static class Program
     {
-       static void Main()
+       private static void Main()
         {
             ServiceBase[] ServicesToRun;
             ServicesToRun = new ServiceBase[]