Fix GenerateConstructorFromMembers to support top-level nullability

src/EditorFeatures/CSharpTest/GenerateFromMembers/GenerateConstructorFromMembers/GenerateConstructorFromMembersTests.cs

@@ -709,6 +709,29 @@ class Z
 }");
         }
 
+        [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsGenerateConstructorFromMembers)]
+        public async Task NullableReferenceType()
+        {
+            await TestInRegularAndScriptAsync(
+@"#nullable enable
+
+class Z
+{
+    [|string? a;|]
+}",
+@"#nullable enable
+
+class Z
+{
+    string? a;
+
+    public Z(string? a{|Navigation:)|}
+    {
+        this.a = a;
+    }
+}");
+        }
+
         [WorkItem(14219, "https://github.com/dotnet/roslyn/issues/14219")]
         [Fact, Trait(Traits.Feature, Traits.Features.CodeActionsGenerateConstructorFromMembers)]
         public async Task TestUnderscoreInName1()

src/Features/Core/Portable/GenerateConstructorFromMembers/GenerateConstructorFromMembersCodeRefactoringProvider.State.cs

@@ -78,8 +78,8 @@ private class State
                     orderby c.Parameters.Length descending
                     where c.Parameters.Length > 0 && c.Parameters.Length < parameters.Length
                     where c.Parameters.All(p => p.RefKind == RefKind.None) && !c.Parameters.Any(p => p.IsParams)
-                    let constructorTypes = c.Parameters.Select(p => p.Type)
-                    let symbolTypes = parameters.Take(c.Parameters.Length).Select(p => p.Type)
+                    let constructorTypes = c.Parameters.Select(p => p.GetTypeWithAnnotatedNullability())
+                    let symbolTypes = parameters.Take(c.Parameters.Length).Select(p => p.GetTypeWithAnnotatedNullability())
                     where constructorTypes.SequenceEqual(symbolTypes)
                     select c;
 

src/Features/Core/Portable/GenerateFromMembers/AbstractGenerateFromMembersCodeRefactoringProvider.cs

@@ -121,9 +121,7 @@ private static bool IsViableProperty(IPropertySymbol property)
 
             foreach (var symbol in selectedMembers)
             {
-                var type = symbol is IFieldSymbol
-                    ? ((IFieldSymbol)symbol).Type
-                    : ((IPropertySymbol)symbol).Type;
+                var type = symbol.GetMemberType();
 
                 var identifierNameParts = IdentifierNameParts.CreateIdentifierNameParts(symbol, rules);
                 if (identifierNameParts.BaseName == "")

src/Workspaces/Core/Portable/Shared/Extensions/SyntaxGeneratorExtensions.cs

@@ -125,7 +125,7 @@ internal static partial class SyntaxGeneratorExtensions
             foreach (var parameter in parameters)
             {
                 var refKind = parameter.RefKind;
-                var parameterType = parameter.Type;
+                var parameterType = parameter.GetTypeWithAnnotatedNullability();
                 var parameterName = parameter.Name;
 
                 if (refKind != RefKind.Out)