## What changes were proposed in this pull request?
When using a higher-order function with the same variable name as the existing columns in `Filter` or something which uses `Analyzer.resolveExpressionBottomUp` during the resolution, e.g.,:
```scala
val df = Seq(
(Seq(1, 9, 8, 7), 1, 2),
(Seq(5, 9, 7), 2, 2),
(Seq.empty, 3, 2),
(null, 4, 2)
).toDF("i", "x", "d")
checkAnswer(df.filter("exists(i, x -> x % d == 0)"),
Seq(Row(Seq(1, 9, 8, 7), 1, 2)))
checkAnswer(df.select("x").filter("exists(i, x -> x % d == 0)"),
Seq(Row(1)))
```
the following exception happens:
```
java.lang.ClassCastException: org.apache.spark.sql.catalyst.expressions.BoundReference cannot be cast to org.apache.spark.sql.catalyst.expressions.NamedExpression
at scala.collection.TraversableLike.$anonfun$map$1(TraversableLike.scala:237)
at scala.collection.mutable.ResizableArray.foreach(ResizableArray.scala:62)
at scala.collection.mutable.ResizableArray.foreach$(ResizableArray.scala:55)
at scala.collection.mutable.ArrayBuffer.foreach(ArrayBuffer.scala:49)
at scala.collection.TraversableLike.map(TraversableLike.scala:237)
at scala.collection.TraversableLike.map$(TraversableLike.scala:230)
at scala.collection.AbstractTraversable.map(Traversable.scala:108)
at org.apache.spark.sql.catalyst.expressions.HigherOrderFunction.$anonfun$functionsForEval$1(higherOrderFunctions.scala:147)
at scala.collection.TraversableLike.$anonfun$map$1(TraversableLike.scala:237)
at scala.collection.immutable.List.foreach(List.scala:392)
at scala.collection.TraversableLike.map(TraversableLike.scala:237)
at scala.collection.TraversableLike.map$(TraversableLike.scala:230)
at scala.collection.immutable.List.map(List.scala:298)
at org.apache.spark.sql.catalyst.expressions.HigherOrderFunction.functionsForEval(higherOrderFunctions.scala:145)
at org.apache.spark.sql.catalyst.expressions.HigherOrderFunction.functionsForEval$(higherOrderFunctions.scala:145)
at org.apache.spark.sql.catalyst.expressions.ArrayExists.functionsForEval$lzycompute(higherOrderFunctions.scala:369)
at org.apache.spark.sql.catalyst.expressions.ArrayExists.functionsForEval(higherOrderFunctions.scala:369)
at org.apache.spark.sql.catalyst.expressions.SimpleHigherOrderFunction.functionForEval(higherOrderFunctions.scala:176)
at org.apache.spark.sql.catalyst.expressions.SimpleHigherOrderFunction.functionForEval$(higherOrderFunctions.scala:176)
at org.apache.spark.sql.catalyst.expressions.ArrayExists.functionForEval(higherOrderFunctions.scala:369)
at org.apache.spark.sql.catalyst.expressions.ArrayExists.nullSafeEval(higherOrderFunctions.scala:387)
at org.apache.spark.sql.catalyst.expressions.SimpleHigherOrderFunction.eval(higherOrderFunctions.scala:190)
at org.apache.spark.sql.catalyst.expressions.SimpleHigherOrderFunction.eval$(higherOrderFunctions.scala:185)
at org.apache.spark.sql.catalyst.expressions.ArrayExists.eval(higherOrderFunctions.scala:369)
at org.apache.spark.sql.catalyst.expressions.GeneratedClass$SpecificPredicate.eval(Unknown Source)
at org.apache.spark.sql.execution.FilterExec.$anonfun$doExecute$3(basicPhysicalOperators.scala:216)
at org.apache.spark.sql.execution.FilterExec.$anonfun$doExecute$3$adapted(basicPhysicalOperators.scala:215)
...
```
because the `UnresolvedAttribute`s in `LambdaFunction` are unexpectedly resolved by the rule.
This pr modified to use a placeholder `UnresolvedNamedLambdaVariable` to prevent unexpected resolution.
## How was this patch tested?
Added a test and modified some tests.
Closes#23320 from ueshin/issues/SPARK-26370/hof_resolution.
Authored-by: Takuya UESHIN <ueshin@databricks.com>
Signed-off-by: Wenchen Fan <wenchen@databricks.com>
3dda58af2b