Fix required completion in records

Author: Youssef1313

src/EditorFeatures/CSharpTest/Completion/CompletionProviders/KeywordCompletionProviderTests.cs

@@ -620,7 +620,9 @@ public async Task TestInCastExpressionThatMightBeParenthesizedExpression2(bool h
         [Theory]
         [InlineData("class")]
         [InlineData("struct")]
-        public async Task SuggestRequiredInClassOrStruct(string type)
+        [InlineData("record")]
+        [InlineData("record struct")]
+        public async Task SuggestRequiredInClassOrStructOrRecord(string type)
         {
             var markup = $$"""
                 {{type}} C

src/Features/CSharp/Portable/Completion/KeywordRecommenders/RequiredKeywordRecommender.cs

@@ -15,11 +15,7 @@ internal class RequiredKeywordRecommender : AbstractSyntacticSingleKeywordRecomm
 {
     private static readonly ISet<SyntaxKind> s_validModifiers = SyntaxKindSet.AllMemberModifiers.Where(s => s is not (SyntaxKind.RequiredKeyword or SyntaxKind.StaticKeyword or SyntaxKind.ReadOnlyKeyword or SyntaxKind.ConstKeyword)).ToSet();
 
-    private static readonly ISet<SyntaxKind> s_validTypeDeclarations = new HashSet<SyntaxKind>(SyntaxFacts.EqualityComparer)
-    {
-        SyntaxKind.StructDeclaration,
-        SyntaxKind.ClassDeclaration,
-    };
+    private static readonly ISet<SyntaxKind> s_validTypeDeclarations = SyntaxKindSet.ClassStructRecordTypeDeclarations;
 
     public RequiredKeywordRecommender()
         : base(SyntaxKind.RequiredKeyword)