[SPARK-13456][SQL] fix creating encoders for case classes defined in Spark shell

## What changes were proposed in this pull request?

case classes defined in REPL are wrapped by line classes, and we have a trick for scala 2.10 REPL to automatically register the wrapper classes to `OuterScope` so that we can use when create encoders.
However, this trick doesn't work right after we upgrade to scala 2.11, and unfortunately the tests are only in scala 2.10, which makes this bug hidden until now.

This PR moves the encoder tests to scala 2.11  `ReplSuite`, and fixes this bug by another approach(the previous trick can't port to scala 2.11 REPL): make `OuterScope` smarter that can detect classes defined in REPL and load the singleton of line wrapper classes automatically.

## How was this patch tested?

the migrated encoder tests in `ReplSuite`

Author: Wenchen Fan <wenchen@databricks.com>

Closes #11410 from cloud-fan/repl.

1 files changed, 2 insertions, 2 deletions

diff --git a/repl/scala-2.10/src/test/scala/org/apache/spark/repl/ReplSuite.scala b/repl/scala-2.10/src/test/scala/org/apache/spark/repl/ReplSuite.scala
index cbcccb11f1..6b9aa5071e 100644
--- a/repl/scala-2.10/src/test/scala/org/apache/spark/repl/ReplSuite.scala
+++ b/repl/scala-2.10/src/test/scala/org/apache/spark/repl/ReplSuite.scala
@@ -288,7 +288,7 @@ class ReplSuite extends SparkFunSuite {
         |import org.apache.spark.sql.Encoder
         |import org.apache.spark.sql.expressions.Aggregator
         |import org.apache.spark.sql.TypedColumn
-        |val simpleSum = new Aggregator[Int, Int, Int] with Serializable {
+        |val simpleSum = new Aggregator[Int, Int, Int] {
         |  def zero: Int = 0                     // The initial value.
         |  def reduce(b: Int, a: Int) = b + a    // Add an element to the running total
         |  def merge(b1: Int, b2: Int) = b1 + b2 // Merge intermediate values.
@@ -347,7 +347,7 @@ class ReplSuite extends SparkFunSuite {
         |import org.apache.spark.sql.expressions.Aggregator
         |import org.apache.spark.sql.TypedColumn
         |/** An `Aggregator` that adds up any numeric type returned by the given function. */
-        |class SumOf[I, N : Numeric](f: I => N) extends Aggregator[I, N, N] with Serializable {
+        |class SumOf[I, N : Numeric](f: I => N) extends Aggregator[I, N, N] {
         |  val numeric = implicitly[Numeric[N]]
         |  override def zero: N = numeric.zero
         |  override def reduce(b: N, a: I): N = numeric.plus(b, f(a))