Add extension order for C# to place the fixes after GenerateMethod.

src/Features/CSharp/Portable/AddParameter/CSharpAddParameterCodeFixProvider.cs

@@ -12,6 +12,7 @@ namespace Microsoft.CodeAnalysis.CSharp.AddParameter
 {
     [ExportCodeFixProvider(LanguageNames.CSharp, Name = PredefinedCodeFixProviderNames.AddParameter), Shared]
     [ExtensionOrder(Before = PredefinedCodeFixProviderNames.GenerateConstructor)]
+    [ExtensionOrder(After = PredefinedCodeFixProviderNames.GenerateMethod)]
     internal class CSharpAddParameterCodeFixProvider : AbstractAddParameterCodeFixProvider<
         ArgumentSyntax,
         AttributeArgumentSyntax,

src/Features/CSharp/Portable/CodeFixes/GenerateMethod/GenerateMethodCodeFixProvider.cs

@@ -50,9 +50,10 @@ internal static class GenerateMethodDiagnosticIds
 
     [ExportCodeFixProvider(LanguageNames.CSharp, Name = PredefinedCodeFixProviderNames.GenerateMethod), Shared]
     [ExtensionOrder(After = PredefinedCodeFixProviderNames.GenerateEnumMember, Before = PredefinedCodeFixProviderNames.PopulateSwitch)]
+    [ExtensionOrder(Before = PredefinedCodeFixProviderNames.AddParameter)]
     internal class GenerateMethodCodeFixProvider : AbstractGenerateMemberCodeFixProvider
     {
-        public override ImmutableArray<string> FixableDiagnosticIds { get; } = 
+        public override ImmutableArray<string> FixableDiagnosticIds { get; } =
             GenerateMethodDiagnosticIds.FixableDiagnosticIds;
 
         protected override bool IsCandidate(SyntaxNode node, SyntaxToken token, Diagnostic diagnostic)