Use null check with pattern-matching instead of object.ReferenceEquals (#13065)

src/ResGen/Program.cs

@@ -147,7 +147,7 @@ using System.Reflection;
     [global::System.ComponentModel.EditorBrowsableAttribute(global::System.ComponentModel.EditorBrowsableState.Advanced)]
     {4} static global::System.Resources.ResourceManager ResourceManager {{
         get {{
-            if (object.ReferenceEquals(resourceMan, null)) {{
+            if (resourceMan is null) {{
                 global::System.Resources.ResourceManager temp = new global::System.Resources.ResourceManager(""{1}.resources.{5}{3}"", typeof({0}).Assembly);
                 resourceMan = temp;
             }}

src/System.Management.Automation/engine/Modules/PSModuleInfo.cs

@@ -1606,7 +1606,7 @@ namespace System.Management.Automation
             if (object.ReferenceEquals(x, y)) return true;
 
             // Check whether any of the compared objects is null.
-            if (object.ReferenceEquals(x, null) || Object.ReferenceEquals(y, null))
+            if (x is null || y is null)
                 return false;
 
             bool result = string.Equals(x.Name, y.Name, StringComparison.OrdinalIgnoreCase) &&

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

@@ -1946,7 +1946,7 @@ namespace System.Management.Automation
 
         public bool Equals(PSMethodInvocationConstraints other)
         {
-            if (ReferenceEquals(null, other))
+            if (other is null)
             {
                 return false;
             }

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

@@ -907,9 +907,9 @@ namespace System.Management.Automation
         /// </summary>
         public static bool operator ==(SemanticVersion v1, SemanticVersion v2)
         {
-            if (object.ReferenceEquals(v1, null))
+            if (v1 is null)
             {
-                return object.ReferenceEquals(v2, null);
+                return v2 is null;
             }
 
             return v1.Equals(v2);

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

@@ -200,7 +200,7 @@ namespace System.Management.Automation.Tracing
         {
             get
             {
-                if (object.ReferenceEquals(_resourceManager, null))
+                if (_resourceManager is null)
                 {
                     _resourceManager = new global::System.Resources.ResourceManager("System.Management.Automation.resources.EventResource", typeof(EventResource).Assembly);
                 }