[SPARK-18189][SQL][FOLLOWUP] Move test from ReplSuite to prevent java.lang.ClassCircularityError

## What changes were proposed in this pull request?
Move the test which is causing java.lang.ClassCircularityError from ReplSuite to DatasetSuite.

## How was this patch tested?
> build/mvn -DskipTests -Phadoop-2.3 -Pyarn -Phive -Phive-thriftserver -Pkinesis-asl -Pmesos clean package
> build/mvn -Dtest=none -DwildcardSuites=org.apache.spark.repl.ReplSuite test

Author: Ergin Seyfe <[email protected]>

Closes #15774 from seyfe/fix_replsuite_test_error_branch2.0.

Author: seyfe

repl/scala-2.11/src/test/scala/org/apache/spark/repl/ReplSuite.scala

@@ -473,21 +473,4 @@ class ReplSuite extends SparkFunSuite {
     assertDoesNotContain("AssertionError", output)
     assertDoesNotContain("Exception", output)
   }
-
-  test("SPARK-18189: Fix serialization issue in KeyValueGroupedDataset") {
-    val resultValue = 12345
-    val output = runInterpreter("local",
-      s"""
-         |val keyValueGrouped = Seq((1, 2), (3, 4)).toDS().groupByKey(_._1)
-         |val mapGroups = keyValueGrouped.mapGroups((k, v) => (k, 1))
-         |val broadcasted = sc.broadcast($resultValue)
-         |
-         |// Using broadcast triggers serialization issue in KeyValueGroupedDataset
-         |val dataset = mapGroups.map(_ => broadcasted.value)
-         |dataset.collect()
-      """.stripMargin)
-    assertDoesNotContain("error:", output)
-    assertDoesNotContain("Exception", output)
-    assertContains(s": Array[Int] = Array($resultValue, $resultValue)", output)
-  }
 }

sql/core/src/test/scala/org/apache/spark/sql/DatasetSuite.scala

@@ -882,6 +882,19 @@ class DatasetSuite extends QueryTest with SharedSQLContext {
       df.withColumn("b", expr("0")).as[ClassData]
         .groupByKey(_.a).flatMapGroups { case (x, iter) => List[Int]() })
   }
+
+  // This is moved from ReplSuite to prevent java.lang.ClassCircularityError.
+  test("SPARK-18189: Fix serialization issue in KeyValueGroupedDataset") {
+    val resultValue = 12345
+    val keyValueGrouped = Seq((1, 2), (3, 4)).toDS().groupByKey(_._1)
+    val mapGroups = keyValueGrouped.mapGroups((k, v) => (k, 1))
+    val broadcasted = spark.sparkContext.broadcast(resultValue)
+
+    // Using broadcast triggers serialization issue in KeyValueGroupedDataset
+    val dataset = mapGroups.map(_ => broadcasted.value)
+
+    assert(dataset.collect() sameElements Array(resultValue, resultValue))
+  }
 }
 
 case class Generic[T](id: T, value: Double)