Add user facing option.

src/Features/CSharp/Portable/UseLocalFunction/CSharpUseLocalFunctionDiagnosticAnalyzer.cs

@@ -82,7 +82,6 @@ private void SyntaxNodeAction(SyntaxNodeAnalysisContext syntaxContext)
                 return;
             }
 
-
             if (localDeclaration.Declaration.Variables.Count != 1)
             {
                 return;

src/VisualStudio/CSharp/Impl/Options/Formatting/StyleViewModel.cs

@@ -523,6 +523,31 @@ public int GetAge()
 //]
     }}
 }}
+";
+
+        private static readonly string s_preferLocalFunctionOverAnonymousFunction = $@"
+using System;
+
+class Customer
+{{
+    public Customer(string value)
+    {{
+//[
+        // {ServicesVSResources.Prefer_colon}
+        int fibonacci(int n)
+        {{
+            return n <= 1 ? 1 : fibonacci(n - 1) + fibonacci(n - 2);
+        }}
+
+        // {ServicesVSResources.Over_colon}
+        Func<int, int> fibonacci = null;
+        fibonacci = (int n) =>
+        {{
+            return n <= 1 ? 1 : fibonacci(n - 1) + fibonacci(n - 2);
+        }};
+//]
+    }}
+}}
 ";
 
         private const string s_preferExpressionBodyForMethods = @"
@@ -747,6 +772,7 @@ internal StyleViewModel(OptionSet optionSet, IServiceProvider serviceProvider) :
             CodeStyleItems.Add(new BooleanCodeStyleOptionViewModel(CSharpCodeStyleOptions.PreferSimpleDefaultExpression, ServicesVSResources.Prefer_simple_default_expression, s_preferSimpleDefaultExpression, s_preferSimpleDefaultExpression, this, optionSet, expressionPreferencesGroupTitle));
             CodeStyleItems.Add(new BooleanCodeStyleOptionViewModel(CSharpCodeStyleOptions.PreferInferredTupleNames, ServicesVSResources.Prefer_inferred_tuple_names, s_preferInferredTupleName, s_preferInferredTupleName, this, optionSet, expressionPreferencesGroupTitle));
             CodeStyleItems.Add(new BooleanCodeStyleOptionViewModel(CSharpCodeStyleOptions.PreferInferredAnonymousTypeMemberNames, ServicesVSResources.Prefer_inferred_anonymous_type_member_names, s_preferInferredAnonymousTypeMemberName, s_preferInferredAnonymousTypeMemberName, this, optionSet, expressionPreferencesGroupTitle));
+            CodeStyleItems.Add(new BooleanCodeStyleOptionViewModel(CSharpCodeStyleOptions.PreferLocalOverAnonymousFunction, ServicesVSResources.Prefer_local_function_over_anonymous_function, s_preferLocalFunctionOverAnonymousFunction, s_preferLocalFunctionOverAnonymousFunction, this, optionSet, expressionPreferencesGroupTitle));
 
             AddExpressionBodyOptions(optionSet, expressionPreferencesGroupTitle);
 

src/VisualStudio/Core/Def/ServicesVSResources.Designer.cs

@@ -1639,6 +1639,15 @@ internal class ServicesVSResources {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Prefere local function over anonymous function.
+        /// </summary>
+        internal static string Prefer_local_function_over_anonymous_function {
+            get {
+                return ResourceManager.GetString("Prefer_local_function_over_anonymous_function", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Prefer null propagation.
         /// </summary>

src/VisualStudio/Core/Def/ServicesVSResources.resx

@@ -959,4 +959,7 @@ Additional information: {1}</value>
   <data name="ChangesNotAllowedWhileCodeIsRunning" xml:space="preserve">
     <value>Changes are not allowed while code is running.</value>
   </data>
+  <data name="Prefer_local_function_over_anonymous_function" xml:space="preserve">
+    <value>Prefere local function over anonymous function</value>
+  </data>
 </root>
\ No newline at end of file