[SPARK-49200][SQL] Fix null type non-codegen ordering exception

### What changes were proposed in this pull request?

Spark mark `NullType` as orderable, and we return 0 when gen comparing code for `NullType`.
```
object OrderUtils {
  def isOrderable(dataType: DataType): Boolean = dataType match {
    case NullType => true
```
This pr makes `NullType` ordering work for non-codegen path to avoid exception.

### Why are the changes needed?

Fix exception:
```sql
set spark.sql.codegen.factoryMode=NO_CODEGEN;
set spark.sql.optimizer.excludedRules=org.apache.spark.sql.catalyst.optimizer.EliminateSorts;

select * from range(10) order by array(null);
```

```
org.apache.spark.SparkIllegalArgumentException: Type PhysicalNullType does not support ordered operations.
    at org.apache.spark.sql.errors.QueryExecutionErrors$.orderedOperationUnsupportedByDataTypeError(QueryExecutionErrors.scala:352)
    at org.apache.spark.sql.catalyst.types.PhysicalNullType.ordering(PhysicalDataType.scala:246)
    at org.apache.spark.sql.catalyst.types.PhysicalNullType.ordering(PhysicalDataType.scala:243)
    at org.apache.spark.sql.catalyst.types.PhysicalArrayType$$anon$1.<init>(PhysicalDataType.scala:283)
    at org.apache.spark.sql.catalyst.types.PhysicalArrayType.interpretedOrdering$lzycompute(PhysicalDataType.scala:281)
    at org.apache.spark.sql.catalyst.types.PhysicalArrayType.interpretedOrdering(PhysicalDataType.scala:281)
    at org.apache.spark.sql.catalyst.types.PhysicalArrayType.ordering(PhysicalDataType.scala:277)
    at org.apache.spark.sql.catalyst.expressions.InterpretedOrdering.compare(ordering.scala:67)
    at org.apache.spark.sql.catalyst.expressions.InterpretedOrdering.compare(ordering.scala:40)
    at org.apache.spark.sql.execution.UnsafeExternalRowSorter$RowComparator.compare(UnsafeExternalRowSorter.java:254)
    at org.apache.spark.util.collection.unsafe.sort.UnsafeInMemorySorter$SortComparator.compare(UnsafeInMemorySorter.java:70)
    at org.apache.spark.util.collection.unsafe.sort.UnsafeInMemorySorter$SortComparator.compare(UnsafeInMemorySorter.java:44)
```

### Does this PR introduce _any_ user-facing change?

yes, bug fix

### How was this patch tested?

add test

### Was this patch authored or co-authored using generative AI tooling?

no

Closes #47707 from ulysses-you/null-ordering.

Authored-by: ulysses-you <[email protected]>
Signed-off-by: youxiduo <[email protected]>

Author: ulysses-you

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

@@ -242,8 +242,7 @@ case class PhysicalMapType(keyType: DataType, valueType: DataType, valueContains
 
 class PhysicalNullType() extends PhysicalDataType with PhysicalPrimitiveType {
   override private[sql] def ordering =
-    throw QueryExecutionErrors.orderedOperationUnsupportedByDataTypeError(
-      "PhysicalNullType")
+    implicitly[Ordering[Unit]].asInstanceOf[Ordering[Any]]
   override private[sql] type InternalType = Any
   @transient private[sql] lazy val tag = typeTag[InternalType]
 }

sql/core/src/test/scala/org/apache/spark/sql/SQLQuerySuite.scala

@@ -31,7 +31,7 @@ import org.apache.commons.io.FileUtils
 import org.apache.spark.{AccumulatorSuite, SPARK_DOC_ROOT, SparkArithmeticException, SparkDateTimeException, SparkException, SparkNumberFormatException, SparkRuntimeException}
 import org.apache.spark.scheduler.{SparkListener, SparkListenerJobStart}
 import org.apache.spark.sql.catalyst.ExtendedAnalysisException
-import org.apache.spark.sql.catalyst.expressions.{GenericRow, Hex}
+import org.apache.spark.sql.catalyst.expressions.{CodegenObjectFactoryMode, GenericRow, Hex}
 import org.apache.spark.sql.catalyst.expressions.Cast._
 import org.apache.spark.sql.catalyst.expressions.aggregate.{Complete, Partial}
 import org.apache.spark.sql.catalyst.optimizer.{ConvertToLocalRelation, NestedColumnAliasingSuite}
@@ -1430,6 +1430,17 @@ class SQLQuerySuite extends QueryTest with SharedSparkSession with AdaptiveSpark
     }
   }
 
+  test("SPARK-49200: Fix null type non-codegen ordering exception") {
+    withSQLConf(
+        SQLConf.CODEGEN_FACTORY_MODE.key -> CodegenObjectFactoryMode.NO_CODEGEN.toString,
+        SQLConf.OPTIMIZER_EXCLUDED_RULES.key ->
+          "org.apache.spark.sql.catalyst.optimizer.EliminateSorts") {
+      checkAnswer(
+        sql("SELECT * FROM range(3) ORDER BY array(null)"),
+        Seq(Row(0), Row(1), Row(2)))
+    }
+  }
+
   test("SPARK-8837: use keyword in column name") {
     withTempView("t") {
       val df = Seq(1 -> "a").toDF("count", "sort")