[SPARK-10684] [SQL] StructType.interpretedOrdering need not to be serialized

Kryo fails with buffer overflow even with max value (2G).

{noformat}
org.apache.spark.SparkException: Kryo serialization failed: Buffer overflow. Available: 0, required: 1
Serialization trace:
containsChild (org.apache.spark.sql.catalyst.expressions.BoundReference)
child (org.apache.spark.sql.catalyst.expressions.SortOrder)
array (scala.collection.mutable.ArraySeq)
ordering (org.apache.spark.sql.catalyst.expressions.InterpretedOrdering)
interpretedOrdering (org.apache.spark.sql.types.StructType)
schema (org.apache.spark.sql.catalyst.expressions.GenericRowWithSchema). To avoid this, increase spark.kryoserializer.buffer.max value.
        at org.apache.spark.serializer.KryoSerializerInstance.serialize(KryoSerializer.scala:263)
        at org.apache.spark.executor.Executor$TaskRunner.run(Executor.scala:240)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615)
        at java.lang.Thread.run(Thread.java:745)
{noformat}

Author: navis.ryu <navis@apache.org>

Closes #8808 from navis/SPARK-10684.

sql/catalyst/src/main/scala/org/apache/spark/sql/types/StructType.scala

@@ -305,7 +305,9 @@ case class StructType(fields: Array[StructField]) extends DataType with Seq[Stru
     f(this) || fields.exists(field => field.dataType.existsRecursively(f))
   }
 
-  private[sql] val interpretedOrdering = InterpretedOrdering.forSchema(this.fields.map(_.dataType))
+  @transient
+  private[sql] lazy val interpretedOrdering =
+    InterpretedOrdering.forSchema(this.fields.map(_.dataType))
 }
 
 object StructType extends AbstractDataType {