spark git commit: [SPARK-9577][SQL] Surface concrete iterator types in various sort classes.

Repository: spark Updated Branches: refs/heads/master 3b0e44490 - 5eb89f67e [SPARK-9577][SQL] Surface concrete iterator types in various sort classes. We often return abstract iterator types in various sort-related classes (e.g. UnsafeKVExternalSorter). It is actually better to return a more

spark git commit: [SPARK-9577][SQL] Surface concrete iterator types in various sort classes.

Repository: spark Updated Branches: refs/heads/branch-1.5 93076ae39 - ebe42b98c [SPARK-9577][SQL] Surface concrete iterator types in various sort classes. We often return abstract iterator types in various sort-related classes (e.g. UnsafeKVExternalSorter). It is actually better to return a