OpenJDK 11: Merging in java.lang.Long (parseUnsignedLong() CharSequence)

This is part of merging upstream changes from OpenJDK 11.28. This CL
adds new API parseUnsignedLong(CharSequence, int, int, int); and adds
unit tests for it.

Bug: 207772338
Test: atest CtsLibcoreOjTestCases:test.java.lang.\
            {Integer,Long}.{ParsingTest,Unsigned}
Change-Id: I160aac221ead0228ea91a7c7e665892b748b254c
4 files changed