Report errors binding to native integer operations with -langversion:8 (#47388)

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

@@ -166,6 +166,8 @@ private BoundExpression BindCompoundAssignment(AssignmentExpressionSyntax node,
 
             BinaryOperatorSignature bestSignature = best.Signature;
 
+            CheckNativeIntegerFeatureAvailability(bestSignature.Kind, node, diagnostics);
+
             if (CheckOverflowAtRuntime)
             {
                 bestSignature = new BinaryOperatorSignature(
@@ -571,6 +573,8 @@ private BoundExpression BindSimpleBinaryOperator(BinaryExpressionSyntax node, Di
                     break;
             }
 
+            CheckNativeIntegerFeatureAvailability(resultOperatorKind, node, diagnostics);
+
             TypeSymbol resultType = signature.ReturnType;
             BoundExpression resultLeft = left;
             BoundExpression resultRight = right;
@@ -2108,6 +2112,8 @@ private BoundExpression BindIncrementOperator(CSharpSyntaxNode node, ExpressionS
 
             var signature = best.Signature;
 
+            CheckNativeIntegerFeatureAvailability(signature.Kind, node, diagnostics);
+
             HashSet<DiagnosticInfo> useSiteDiagnostics = null;
             var resultConversion = Conversions.ClassifyConversionFromType(signature.ReturnType, operandType, ref useSiteDiagnostics);
             diagnostics.Add(node, useSiteDiagnostics);
@@ -2479,6 +2485,8 @@ private BoundExpression BindUnaryOperatorCore(CSharpSyntaxNode node, string oper
             var resultMethod = signature.Method;
             var resultConstant = FoldUnaryOperator(node, resultOperatorKind, resultOperand, resultType.SpecialType, diagnostics);
 
+            CheckNativeIntegerFeatureAvailability(resultOperatorKind, node, diagnostics);
+
             return new BoundUnaryOperator(
                 node,
                 resultOperatorKind.WithOverflowChecksIfApplicable(CheckOverflowAtRuntime),
@@ -3994,5 +4002,27 @@ private static ConstantValue FoldConditionalOperator(BoundExpression condition,
                 return ConstantValue.Bad;
             }
         }
+
+        private static void CheckNativeIntegerFeatureAvailability(BinaryOperatorKind operatorKind, SyntaxNode syntax, DiagnosticBag diagnostics)
+        {
+            switch (operatorKind & BinaryOperatorKind.TypeMask)
+            {
+                case BinaryOperatorKind.NInt:
+                case BinaryOperatorKind.NUInt:
+                    CheckFeatureAvailability(syntax, MessageID.IDS_FeatureNativeInt, diagnostics);
+                    break;
+            }
+        }
+
+        private static void CheckNativeIntegerFeatureAvailability(UnaryOperatorKind operatorKind, SyntaxNode syntax, DiagnosticBag diagnostics)
+        {
+            switch (operatorKind & UnaryOperatorKind.TypeMask)
+            {
+                case UnaryOperatorKind.NInt:
+                case UnaryOperatorKind.NUInt:
+                    CheckFeatureAvailability(syntax, MessageID.IDS_FeatureNativeInt, diagnostics);
+                    break;
+            }
+        }
     }
 }