Update HashMap, HashSet, LinkedHashMap to JDK8u60.

Added tests for:
 - entrySet()/keySet()/values() spliterators (LinkedHashMap
   has completely new implementations)
 - LinkedHashMap.eldest (Android specific API, previously
   existed but was untested)
 - naming of nested class LinkedHashMap.LinkedHashMapEntry
 - tweaked test for Map.getOrDefault() method so it's useful
   for LinkedHashMap

This CL doesn't touch HashSetTest since it already covered
spliterator() and serialization.

Test: Ran all libcore tests.

Bug: 29935305
Change-Id: I9d991a08c403b83b15e9c88ce97cbd5cd77a8bcf
11 files changed