[Spark-3222] [SQL] Cross join support in HiveQL

We can simple treat cross join as inner join without join conditions.

Author: Daoyuan Wang <daoyuan.wang@intel.com>
Author: adrian-wang <daoyuanwong@gmail.com>

Closes apache#2124 from adrian-wang/crossjoin and squashes the following commits:

8c9b7c5 [Daoyuan Wang] add a test
7d47bbb [adrian-wang] add cross join support for hql

Author: adrian-wang

sql/hive/compatibility/src/test/scala/org/apache/spark/sql/hive/execution/HiveCompatibilitySuite.scala

@@ -310,6 +310,7 @@ class HiveCompatibilitySuite extends HiveQueryFileTest with BeforeAndAfter {
     "create_nested_type",
     "create_skewed_table1",
     "create_struct_table",
+    "cross_join",
     "ct_case_insensitive",
     "database_location",
     "database_properties",

sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveQl.scala

@@ -772,6 +772,7 @@ private[hive] object HiveQl {
 
       val joinType = joinToken match {
         case "TOK_JOIN" => Inner
+        case "TOK_CROSSJOIN" => Inner
         case "TOK_RIGHTOUTERJOIN" => RightOuter
         case "TOK_LEFTOUTERJOIN" => LeftOuter
         case "TOK_FULLOUTERJOIN" => FullOuter