Support range variables in C# F1 help

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

@@ -153,6 +153,13 @@ private bool TryGetTextForSymbol(SyntaxToken token, SemanticModel semanticModel,
                 symbol = ((ILocalSymbol)symbol).Type;
             }
 
+            // Range variable: use the type
+            if (symbol is IRangeVariableSymbol)
+            {
+                var info = semanticModel.GetTypeInfo(token.Parent, CancellationToken.None);
+                symbol = info.Type;
+            }
+
             // Just use syntaxfacts for operators
             if (symbol is IMethodSymbol && ((IMethodSymbol)symbol).MethodKind == MethodKind.BuiltinOperator)
             {

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

@@ -506,5 +506,22 @@ void M()
     }
 }", "dynamic_CSharpKeyword");
         }
+
+        [Fact, Trait(Traits.Feature, Traits.Features.F1Help)]
+        public void TestRangeVariable()
+        {
+            Test(@"using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Threading.Tasks;
+
+class Program
+{
+    static void Main(string[] args)
+    {
+        var zzz = from y in args select [||]y;
+    }
+}", "System.String");
+        }
     }
 }