Fixing comma operator

Jint.Tests.Ecma/Ecma/11.14.cs

@@ -2,6 +2,7 @@ using Xunit;
 
 namespace Jint.Tests.Ecma
 {
+    [Trait("Category", "Pass")]
     public class Test_11_14 : EcmaTest
     {
         [Fact]

Jint/Runtime/ExpressionIntepreter.cs

@@ -851,7 +851,7 @@ namespace Jint.Runtime
             var result = Undefined.Instance;
             foreach (var expression in sequenceExpression.Expressions)
             {
-                result = _engine.EvaluateExpression(expression);
+                result = _engine.GetValue(_engine.EvaluateExpression(expression));
             }
 
             return result;