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

This is part of merging upstream changes from OpenJDK 11.28. This CL
updates parseUnsignedLong(long, int); and adds unit tests.

Bug: 207772338
Test: atest CtsLibcoreOjTestCases:test.java.lang.\
            {Integer,Long}.{ParsingTest,Unsigned}
Change-Id: I0088a1d0358c209178ee773e077504e6843271f6
2 files changed