[SQL][SPARK-7142]: Minor enhancement to BooleanSimplification Optimizer rule. Incorporate review comments

[saucam]

Adding changes suggested by @cloud-fan in #5700

cc @marmbrus

[srowen]

(Probably deserves a more descriptive title connecting it to the purpose of the JIRA)

[SparkQA]

Test build #42332 has finished for PR 8716 at commit 2861453.

• This patch passes all tests.
• This patch merges cleanly.
• This patch adds the following public classes (experimental):
  • class ShuffleDependency[K: ClassTag, V: ClassTag, C: ClassTag](
  • case class ExecutorLostFailure(execId: String, isNormalExit: Boolean = false)
  • class CoGroupedRDD[K: ClassTag](
  • class ShuffledRDD[K: ClassTag, V: ClassTag, C: ClassTag](
  • class ExecutorLossReason(val message: String) extends Serializable
  • case class ExecutorExited(exitCode: Int, isNormalExit: Boolean, reason: String)
  • case class RemoveExecutor(executorId: String, reason: ExecutorLossReason)
  • case class GetExecutorLossReason(executorId: String) extends CoarseGrainedClusterMessage
  • class StringIndexer(JavaEstimator, HasInputCol, HasOutputCol, HasHandleInvalid):
  • class HasHandleInvalid(Params):
  • case class ConvertToSafeNode(conf: SQLConf, child: LocalNode) extends UnaryLocalNode(conf)
  • case class ConvertToUnsafeNode(conf: SQLConf, child: LocalNode) extends UnaryLocalNode(conf)
  • case class FilterNode(conf: SQLConf, condition: Expression, child: LocalNode)
  • case class HashJoinNode(
  • case class LimitNode(conf: SQLConf, limit: Int, child: LocalNode) extends UnaryLocalNode(conf)
  • abstract class LocalNode(conf: SQLConf) extends TreeNode[LocalNode] with Logging
  • abstract class LeafLocalNode(conf: SQLConf) extends LocalNode(conf)
  • abstract class UnaryLocalNode(conf: SQLConf) extends LocalNode(conf)
  • abstract class BinaryLocalNode(conf: SQLConf) extends LocalNode(conf)
  • case class ProjectNode(conf: SQLConf, projectList: Seq[NamedExpression], child: LocalNode)
  • case class SeqScanNode(conf: SQLConf, output: Seq[Attribute], data: Seq[InternalRow])
  • case class UnionNode(conf: SQLConf, children: Seq[LocalNode]) extends LocalNode(conf)

[cloud-fan]

LGTM