Add "refactoring" as an alias for "silent" in .editorconfig

src/Workspaces/Core/Portable/CodeStyle/CodeStyleHelpers.cs

@@ -98,6 +98,7 @@ public static bool TryParseNotification(string value, out NotificationOption not
                     notification = NotificationOption.None;
                     return true;
 
+                case EditorConfigSeverityStrings.Refactoring:
                 case EditorConfigSeverityStrings.Silent:
                     notification = NotificationOption.Silent;
                     return true;

src/Workspaces/Core/Portable/NamingStyles/EditorConfig/EditorConfigNamingStyleParser_NamingRule.cs

@@ -52,6 +52,7 @@ private static ReportDiagnostic ParseEnforcementLevel(string ruleSeverity)
                 case EditorConfigSeverityStrings.None:
                     return ReportDiagnostic.Suppress;
 
+                case EditorConfigSeverityStrings.Refactoring:
                 case EditorConfigSeverityStrings.Silent:
                     return ReportDiagnostic.Hidden;
 

src/Workspaces/Core/Portable/NamingStyles/EditorConfig/EditorConfigSeverityStrings.cs

@@ -5,6 +5,7 @@ namespace Microsoft.CodeAnalysis
     internal static class EditorConfigSeverityStrings
     {
         public const string None = "none";
+        public const string Refactoring = "refactoring";
         public const string Silent = "silent";
         public const string Suggestion = "suggestion";
         public const string Warning = "warning";

src/Workspaces/CoreTest/CodeStyle/EditorConfigCodeStyleParserTests.cs

@@ -14,12 +14,14 @@ public class EditorConfigCodeStyleParserTests
     {
         [Theory]
         [InlineData("true:none", true, ReportDiagnostic.Suppress)]
+        [InlineData("true:refactoring", true, ReportDiagnostic.Hidden)]
         [InlineData("true:silent", true, ReportDiagnostic.Hidden)]
         [InlineData("true:suggestion", true, ReportDiagnostic.Info)]
         [InlineData("true:warning", true, ReportDiagnostic.Warn)]
         [InlineData("true:error", true, ReportDiagnostic.Error)]
         [InlineData("true", false, ReportDiagnostic.Hidden)]
         [InlineData("false:none", false, ReportDiagnostic.Suppress)]
+        [InlineData("false:refactoring", false, ReportDiagnostic.Hidden)]
         [InlineData("false:silent", false, ReportDiagnostic.Hidden)]
         [InlineData("false:suggestion", false, ReportDiagnostic.Info)]
         [InlineData("false:warning", false, ReportDiagnostic.Warn)]