Do not expose operation nodes for BoundRangeVariables in C# query expression

These nodes contain the bound parameter reference to the underlying lambda parameter, which is now exposed.
Fixes #23079

src/Compilers/CSharp/Portable/Binder/Binder.WithQueryLambdaParametersBinder.cs

@@ -43,14 +43,14 @@ protected override BoundExpression BindRangeVariable(SimpleNameSyntax node, Rang
                         // the range variable maps directly to a use of the parameter of that name
                         var value = base.parameterMap[qv.Name];
                         Debug.Assert(value.Count == 1);
-                        translation = new BoundParameter(node, value.Single()) { WasCompilerGenerated = true };
+                        translation = new BoundParameter(node, value.Single());
                     }
                     else
                     {
                         // if the query variable map for this variable is non empty, we always start with the current
                         // lambda's first parameter, which is a transparent identifier.
                         Debug.Assert(base.lambdaSymbol.Parameters[0].Name.StartsWith(transparentIdentifierPrefix, StringComparison.Ordinal));
-                        translation = new BoundParameter(node, base.lambdaSymbol.Parameters[0]) { WasCompilerGenerated = true };
+                        translation = new BoundParameter(node, base.lambdaSymbol.Parameters[0]);
                         for (int i = path.Length - 1; i >= 0; i--)
                         {
                             var nextField = path[i];

src/Compilers/CSharp/Portable/Operations/CSharpOperationFactory.cs

@@ -239,6 +239,8 @@ private IOperation CreateInternal(BoundNode boundNode)
                     return CreateBoundQueryClauseOperation((BoundQueryClause)boundNode);
                 case BoundKind.DelegateCreationExpression:
                     return CreateBoundDelegateCreationExpressionOperation((BoundDelegateCreationExpression)boundNode);
+                case BoundKind.RangeVariable:
+                    return Create(((BoundRangeVariable)boundNode).Value);
                 default:
                     Optional<object> constantValue = ConvertToOptional((boundNode as BoundExpression)?.ConstantValue);
                     bool isImplicit = boundNode.WasCompilerGenerated;

src/Compilers/CSharp/Test/Semantic/IOperation/IOperationTests_IForLoopStatement.cs

@@ -1929,7 +1929,7 @@ static void Main(string[] args)
                                                                   IArgumentOperation (ArgumentKind.Explicit, Matching Parameter: z) (OperationKind.Argument, Type: null, IsImplicit) (Syntax: 'x.ToString()')
                                                                     IInvocationOperation (virtual System.String System.Char.ToString()) (OperationKind.Invocation, Type: System.String) (Syntax: 'x.ToString()')
                                                                       Instance Receiver: 
-                                                                        IOperation:  (OperationKind.None, Type: null) (Syntax: 'x')
+                                                                        IParameterReferenceOperation: x (OperationKind.ParameterReference, Type: System.Char) (Syntax: 'x')
                                                                       Arguments(0)
                                                                     InConversion: CommonConversion (Exists: True, IsIdentity: True, IsNumeric: False, IsReference: False, IsUserDefined: False) (MethodSymbol: null)
                                                                     OutConversion: CommonConversion (Exists: True, IsIdentity: True, IsNumeric: False, IsReference: False, IsUserDefined: False) (MethodSymbol: null)
@@ -1946,7 +1946,9 @@ static void Main(string[] args)
                                               IBlockOperation (1 statements) (OperationKind.Block, Type: null, IsImplicit) (Syntax: 'z')
                                                 IReturnOperation (OperationKind.Return, Type: null, IsImplicit) (Syntax: 'z')
                                                   ReturnedValue: 
-                                                    IOperation:  (OperationKind.None, Type: null) (Syntax: 'z')
+                                                    IPropertyReferenceOperation: System.String <anonymous type: System.Char x, System.String z>.z { get; } (OperationKind.PropertyReference, Type: System.String, IsImplicit) (Syntax: 'z')
+                                                      Instance Receiver: 
+                                                        IParameterReferenceOperation: <>h__TransparentIdentifier0 (OperationKind.ParameterReference, Type: <anonymous type: System.Char x, System.String z>) (Syntax: 'z')
                                         InConversion: CommonConversion (Exists: True, IsIdentity: True, IsNumeric: False, IsReference: False, IsUserDefined: False) (MethodSymbol: null)
                                         OutConversion: CommonConversion (Exists: True, IsIdentity: True, IsNumeric: False, IsReference: False, IsUserDefined: False) (MethodSymbol: null)
                                 InConversion: CommonConversion (Exists: True, IsIdentity: True, IsNumeric: False, IsReference: False, IsUserDefined: False) (MethodSymbol: null)
@@ -1958,7 +1960,7 @@ static void Main(string[] args)
                                       IBlockOperation (1 statements) (OperationKind.Block, Type: null, IsImplicit) (Syntax: 'w')
                                         IReturnOperation (OperationKind.Return, Type: null, IsImplicit) (Syntax: 'w')
                                           ReturnedValue: 
-                                            IOperation:  (OperationKind.None, Type: null) (Syntax: 'w')
+                                            IParameterReferenceOperation: w (OperationKind.ParameterReference, Type: System.String) (Syntax: 'w')
                                 InConversion: CommonConversion (Exists: True, IsIdentity: True, IsNumeric: False, IsReference: False, IsUserDefined: False) (MethodSymbol: null)
                                 OutConversion: CommonConversion (Exists: True, IsIdentity: True, IsNumeric: False, IsReference: False, IsUserDefined: False) (MethodSymbol: null)
           Initializer: 
@@ -2091,7 +2093,7 @@ private static IEnumerable<string> fun()
                                                         IArgumentOperation (ArgumentKind.Explicit, Matching Parameter: z) (OperationKind.Argument, Type: null, IsImplicit) (Syntax: 'x.ToString()')
                                                           IInvocationOperation (virtual System.String System.Char.ToString()) (OperationKind.Invocation, Type: System.String) (Syntax: 'x.ToString()')
                                                             Instance Receiver: 
-                                                              IOperation:  (OperationKind.None, Type: null) (Syntax: 'x')
+                                                              IParameterReferenceOperation: x (OperationKind.ParameterReference, Type: System.Char) (Syntax: 'x')
                                                             Arguments(0)
                                                           InConversion: CommonConversion (Exists: True, IsIdentity: True, IsNumeric: False, IsReference: False, IsUserDefined: False) (MethodSymbol: null)
                                                           OutConversion: CommonConversion (Exists: True, IsIdentity: True, IsNumeric: False, IsReference: False, IsUserDefined: False) (MethodSymbol: null)
@@ -2108,7 +2110,9 @@ private static IEnumerable<string> fun()
                                     IBlockOperation (1 statements) (OperationKind.Block, Type: null, IsImplicit) (Syntax: 'z')
                                       IReturnOperation (OperationKind.Return, Type: null, IsImplicit) (Syntax: 'z')
                                         ReturnedValue: 
-                                          IOperation:  (OperationKind.None, Type: null) (Syntax: 'z')
+                                          IPropertyReferenceOperation: System.String <anonymous type: System.Char x, System.String z>.z { get; } (OperationKind.PropertyReference, Type: System.String, IsImplicit) (Syntax: 'z')
+                                            Instance Receiver: 
+                                              IParameterReferenceOperation: <>h__TransparentIdentifier0 (OperationKind.ParameterReference, Type: <anonymous type: System.Char x, System.String z>) (Syntax: 'z')
                               InConversion: CommonConversion (Exists: True, IsIdentity: True, IsNumeric: False, IsReference: False, IsUserDefined: False) (MethodSymbol: null)
                               OutConversion: CommonConversion (Exists: True, IsIdentity: True, IsNumeric: False, IsReference: False, IsUserDefined: False) (MethodSymbol: null)
                       InConversion: CommonConversion (Exists: True, IsIdentity: True, IsNumeric: False, IsReference: False, IsUserDefined: False) (MethodSymbol: null)
@@ -2120,7 +2124,7 @@ private static IEnumerable<string> fun()
                             IBlockOperation (1 statements) (OperationKind.Block, Type: null, IsImplicit) (Syntax: 'w')
                               IReturnOperation (OperationKind.Return, Type: null, IsImplicit) (Syntax: 'w')
                                 ReturnedValue: 
-                                  IOperation:  (OperationKind.None, Type: null) (Syntax: 'w')
+                                  IParameterReferenceOperation: w (OperationKind.ParameterReference, Type: System.String) (Syntax: 'w')
                       InConversion: CommonConversion (Exists: True, IsIdentity: True, IsNumeric: False, IsReference: False, IsUserDefined: False) (MethodSymbol: null)
                       OutConversion: CommonConversion (Exists: True, IsIdentity: True, IsNumeric: False, IsReference: False, IsUserDefined: False) (MethodSymbol: null)
 ";

src/Compilers/CSharp/Test/Semantic/IOperation/IOperationTests_IParameterReferenceExpression.cs

@@ -175,7 +175,7 @@ public void M(List<Customer> customers)
                       ReturnedValue: 
                         IPropertyReferenceOperation: System.String Customer.Name { get; set; } (OperationKind.PropertyReference, Type: System.String) (Syntax: 'cust.Name')
                           Instance Receiver: 
-                            IOperation:  (OperationKind.None, Type: null) (Syntax: 'cust')
+                            IParameterReferenceOperation: cust (OperationKind.ParameterReference, Type: Customer) (Syntax: 'cust')
             InConversion: CommonConversion (Exists: True, IsIdentity: True, IsNumeric: False, IsReference: False, IsUserDefined: False) (MethodSymbol: null)
             OutConversion: CommonConversion (Exists: True, IsIdentity: True, IsNumeric: False, IsReference: False, IsUserDefined: False) (MethodSymbol: null)
 ";

src/Compilers/CSharp/Test/Semantic/IOperation/IOperationTests_IParenthesized.cs

@@ -443,7 +443,7 @@ static object M1(int[] a)
                               ReturnedValue: 
                                 IUnaryOperation (UnaryOperatorKind.Minus) (OperationKind.UnaryOperator, Type: System.Int32) (Syntax: '-r')
                                   Operand: 
-                                    IOperation:  (OperationKind.None, Type: null) (Syntax: 'r')
+                                    IParameterReferenceOperation: r (OperationKind.ParameterReference, Type: System.Int32) (Syntax: 'r')
                     InConversion: CommonConversion (Exists: True, IsIdentity: True, IsNumeric: False, IsReference: False, IsUserDefined: False) (MethodSymbol: null)
                     OutConversion: CommonConversion (Exists: True, IsIdentity: True, IsNumeric: False, IsReference: False, IsUserDefined: False) (MethodSymbol: null)
 ";