Fix F1 keywords clashing for !_CSharpKeyword

src/VisualStudio/CSharp/Impl/LanguageService/CSharpHelpContextService.cs

@@ -206,6 +206,13 @@ private bool TryGetTextForSymbol(SyntaxToken token, SemanticModel semanticModel,
 
         private static bool TryGetTextForOperator(SyntaxToken token, Document document, out string text)
         {
+            if (token.IsKind(SyntaxKind.ExclamationToken) &&
+                token.Parent.IsKind(SyntaxKind.SuppressNullableWarningExpression))
+            {
+                text = Keyword("nullForgiving");
+                return true;
+            }
+
             var syntaxFacts = document.GetLanguageService<ISyntaxFactsService>();
             if (syntaxFacts.IsOperator(token) || syntaxFacts.IsPredefinedOperator(token) || SyntaxFacts.IsAssignmentExpressionOperatorToken(token.Kind()))
             {

src/VisualStudio/CSharp/Test/F1Help/F1HelpTests.cs

@@ -746,5 +746,34 @@ void goo()
     }
 }", "nameof");
         }
+
+        [WorkItem(46988, "https://github.com/dotnet/roslyn/issues/46988")]
+        [Fact, Trait(Traits.Feature, Traits.Features.F1Help)]
+        public async Task TestNullForgiving()
+        {
+            await Test_KeywordAsync(
+@"#nullable enable
+class C
+{
+    int goo(string? x)
+    {
+        return x[||]!.GetHashCode();
+    }
+}", "nullForgiving");
+        }
+
+        [WorkItem(46988, "https://github.com/dotnet/roslyn/issues/46988")]
+        [Fact, Trait(Traits.Feature, Traits.Features.F1Help)]
+        public async Task TestLogicalNot()
+        {
+            await Test_KeywordAsync(
+@"class C
+{
+    bool goo(bool x)
+    {
+        return [||]!x;
+    }
+}", "!");
+        }
     }
 }