OpenJDK 11: Merging in java.util.Collection

This is part of merging upstream changes from OpenJDK 11.28. This CL
updates java.util.Collection; and adds unit tests for it.

There is a new API added in java.util.Collection:
 * <T> T[] toArray(java.util.function.IntFunction<T[]>);

Some tck tests were updated to work with new toArray(IntFunction) method.

Bug: 199905893
Test: atest CtsLibcoreOjTestCases:test.java.util.Collection.{\
      BiggernYours,CollectionDefaults,HotPotatoes,IteratorAtEnd,SetFactories}
Change-Id: If4b45e450bfcee50b5c80de36db97d37e214a1a3
31 files changed