[SPARK-9632] [SQL] [HOT-FIX] Fix build.

seems https://github.com/apache/spark/pull/7955 breaks the build.

Author: Yin Huai <yhuai@databricks.com>

Closes #8001 from yhuai/SPARK-9632-fixBuild and squashes the following commits:

6c257dd [Yin Huai] Fix build.

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/rows.scala

@@ -20,6 +20,7 @@ package org.apache.spark.sql.catalyst.expressions
 import org.apache.spark.sql.Row
 import org.apache.spark.sql.catalyst.InternalRow
 import org.apache.spark.sql.types._
+import org.apache.spark.unsafe.types.{CalendarInterval, UTF8String}
 
 /**
  * An extended interface to [[InternalRow]] that allows the values for each column to be updated.