Update wrong error code in test comments (#45917)

src/Compilers/CSharp/Test/Emit/CodeGen/CodeGenInParametersTests.cs

@@ -1178,10 +1178,10 @@ class Program
 
             var comp = CreateCompilationWithMscorlib45(text, new[] { ValueTupleRef, SystemRuntimeFacadeRef });
             comp.VerifyDiagnostics(
-                // (18,20): error CS8410: Cannot return variable 'in int' by writable reference because it is a readonly variable
+                // (18,20): error CS8333: Cannot return variable 'in int' by writable reference because it is a readonly variable
                 //         return ref arg1;
                 Diagnostic(ErrorCode.ERR_RefReturnReadonlyNotField, "arg1").WithArguments("variable", "in int").WithLocation(18, 20),
-                // (23,20): error CS8411: Members of variable 'in (int Alice, int Bob)' cannot be returned by writable reference because it is a readonly variable
+                // (23,20): error CS8334: Members of variable 'in (int Alice, int Bob)' cannot be returned by writable reference because it is a readonly variable
                 //         return ref arg2.Alice;
                 Diagnostic(ErrorCode.ERR_RefReturnReadonlyNotField2, "arg2.Alice").WithArguments("variable", "in (int Alice, int Bob)").WithLocation(23, 20)
             );
@@ -1269,10 +1269,10 @@ class Program
 
             var comp = CreateCompilationWithMscorlib45(text, new[] { ValueTupleRef, SystemRuntimeFacadeRef });
             comp.VerifyDiagnostics(
-                // (10,24): error CS8410: Cannot return variable 'in int' by writable reference because it is a readonly variable
+                // (10,24): error CS8333: Cannot return variable 'in int' by writable reference because it is a readonly variable
                 //             return ref arg1;
                 Diagnostic(ErrorCode.ERR_RefReturnReadonlyNotField, "arg1").WithArguments("variable", "in int").WithLocation(10, 24),
-                // (14,24): error CS8411: Members of variable 'in (int Alice, int Bob)' cannot be returned by writable reference because it is a readonly variable
+                // (14,24): error CS8334: Members of variable 'in (int Alice, int Bob)' cannot be returned by writable reference because it is a readonly variable
                 //             return ref arg2.Alice;
                 Diagnostic(ErrorCode.ERR_RefReturnReadonlyNotField2, "arg2.Alice").WithArguments("variable", "in (int Alice, int Bob)").WithLocation(14, 24)
             );
@@ -1388,10 +1388,10 @@ class Program
 
             var comp = CreateCompilationWithMscorlib45(text, new[] { ValueTupleRef, SystemRuntimeFacadeRef });
             comp.VerifyDiagnostics(
-                // (12,28): error CS8410: Cannot return variable 'in int' by writable reference because it is a readonly variable
+                // (12,28): error CS8333: Cannot return variable 'in int' by writable reference because it is a readonly variable
                 //                 return ref arg11;
                 Diagnostic(ErrorCode.ERR_RefReturnReadonlyNotField, "arg11").WithArguments("variable", "in int").WithLocation(12, 28),
-                // (16,28): error CS8411: Members of variable 'in (int Alice, int Bob)' cannot be returned by writable reference because it is a readonly variable
+                // (16,28): error CS8334: Members of variable 'in (int Alice, int Bob)' cannot be returned by writable reference because it is a readonly variable
                 //                 return ref arg21.Alice;
                 Diagnostic(ErrorCode.ERR_RefReturnReadonlyNotField2, "arg21.Alice").WithArguments("variable", "in (int Alice, int Bob)").WithLocation(16, 28)
                 );