[SPARK-11732] Removes some MiMa false positives

This adds an extra filter for private or protected classes. We only filter for package private right now.

Author: Timothy Hunter <timhunter@databricks.com>

Closes #9697 from thunterdb/spark-11732.

project/MimaExcludes.scala

@@ -54,12 +54,7 @@ object MimaExcludes {
       MimaBuild.excludeSparkClass("streaming.flume.FlumeTestUtils") ++
       MimaBuild.excludeSparkClass("streaming.flume.PollingFlumeTestUtils") ++
       Seq(
-        ProblemFilters.exclude[MissingMethodProblem](
-          "org.apache.spark.ml.classification.LogisticCostFun.this"),
-        ProblemFilters.exclude[MissingMethodProblem](
-          "org.apache.spark.ml.classification.LogisticAggregator.add"),
-        ProblemFilters.exclude[MissingMethodProblem](
-          "org.apache.spark.ml.classification.LogisticAggregator.count"),
+        // MiMa does not deal properly with sealed traits
         ProblemFilters.exclude[MissingMethodProblem](
           "org.apache.spark.ml.classification.LogisticRegressionSummary.featuresCol")
       ) ++ Seq(

tools/src/main/scala/org/apache/spark/tools/GenerateMIMAIgnore.scala

@@ -72,7 +72,9 @@ object GenerateMIMAIgnore {
         val classSymbol = mirror.classSymbol(Class.forName(className, false, classLoader))
         val moduleSymbol = mirror.staticModule(className)
         val directlyPrivateSpark =
-          isPackagePrivate(classSymbol) || isPackagePrivateModule(moduleSymbol)
+          isPackagePrivate(classSymbol) ||
+          isPackagePrivateModule(moduleSymbol) ||
+          classSymbol.isPrivate
         val developerApi = isDeveloperApi(classSymbol) || isDeveloperApi(moduleSymbol)
         val experimental = isExperimental(classSymbol) || isExperimental(moduleSymbol)
         /* Inner classes defined within a private[spark] class or object are effectively