Have 'use explicit type' add usings as necessary to minimally qualify the type (#79574)

Author: CyrusNajmabadi

src/Analyzers/CSharp/CodeFixes/UseImplicitOrExplicitType/UseExplicitTypeCodeFixProvider.cs

@@ -17,6 +17,7 @@
 using Microsoft.CodeAnalysis.LanguageService;
 using Microsoft.CodeAnalysis.PooledObjects;
 using Microsoft.CodeAnalysis.Shared.Extensions;
+using Microsoft.CodeAnalysis.Simplification;
 using Roslyn.Utilities;
 
 namespace Microsoft.CodeAnalysis.CSharp.TypeStyle;
@@ -224,13 +225,14 @@ private static ExpressionSyntax GenerateTupleDeclaration(
             .WithTrailingTrivia(parensDesignation.GetTrailingTrivia());
     }
 
-    private static SyntaxNode GenerateTypeDeclaration(TypeSyntax typeSyntax, ITypeSymbol newTypeSymbol)
+    private static TypeSyntax GenerateTypeDeclaration(TypeSyntax typeSyntax, ITypeSymbol newTypeSymbol)
     {
         // We're going to be passed through the simplifier.  Tell it to not just convert this back to var (as
         // that would defeat the purpose of this refactoring entirely).
         var newTypeSyntax = newTypeSymbol
-                     .GenerateTypeSyntax(allowVar: false)
-                     .WithTriviaFrom(typeSyntax);
+            .GenerateTypeSyntax(allowVar: false)
+            .WithAdditionalAnnotations(Simplifier.AddImportsAnnotation)
+            .WithTriviaFrom(typeSyntax);
 
         return newTypeSyntax;
     }

src/Analyzers/CSharp/Tests/UseImplicitOrExplicitType/UseExplicitTypeTests.cs

@@ -2653,7 +2653,9 @@ void M()
             }
             """, new TestParameters(options: ExplicitTypeEverywhere()));
 
-    [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/23907")]
+    [Fact]
+    [WorkItem("https://github.com/dotnet/roslyn/issues/23907")]
+    [WorkItem("https://github.com/dotnet/roslyn/issues/24034")]
     public async Task WithNormalFuncSynthesizedLambdaType()
     {
         var before = """
@@ -2666,11 +2668,13 @@ void Method()
             }
             """;
         var after = """
+            using System;
+
             class Program
             {
                 void Method()
                 {
-                    System.Func<int, string> x = (int i) => i.ToString();
+                    Func<int, string> x = (int i) => i.ToString();
                 }
             }
             """;