Add escaped backtick test

Author: dilipbiswal

sql/hive/src/test/scala/org/apache/spark/sql/hive/HiveQlSuite.scala

@@ -217,4 +217,13 @@ class HiveQlSuite extends SparkFunSuite with BeforeAndAfterAll {
         |LATERAL VIEW explode(`gentab1`.`gencol1`) `gentab2` AS `gencol2`
       """.stripMargin)
   }
+
+  test("use escaped backticks in output of Generator") {
+    val plan = parser.parsePlan(
+      """SELECT `gen``tab2`.`gen``col2`
+        |FROM `default`.`src`
+        |LATERAL VIEW explode(array(array(1, 2, 3))) `gen``tab1` AS `gen``col1`
+        |LATERAL VIEW explode(`gen``tab1`.`gen``col1`) `gen``tab2` AS `gen``col2`
+      """.stripMargin)
+  }
 }

sql/hive/src/test/scala/org/apache/spark/sql/hive/execution/SQLQuerySuite.scala

@@ -262,6 +262,10 @@ class SQLQuerySuite extends QueryTest with SQLTestUtils with TestHiveSingleton {
     checkAnswer(
       sql("SELECT `a`.`ints` FROM nestedArray LATERAL VIEW explode(a.b) `a` AS `ints`"),
       Row(1) :: Row(2) :: Row(3) :: Nil)
+
+    checkAnswer(
+      sql("SELECT `weird``tab`.`weird``col` FROM nestedArray LATERAL VIEW explode(a.b) `weird``tab` AS `weird``col`"),
+      Row(1) :: Row(2) :: Row(3) :: Nil)
   }
 
   test("SPARK-4512 Fix attribute reference resolution error when using SORT BY") {