OpenJDK 11: Merging in java.lang.Long (toString(long) and helpers)

This is part of merging upstream changes from OpenJDK 11.28. This CL
updates toString(long) and its helpers methods:

 * int getChars(long i, int index, byte[] buf)
 * int stringSize(long x)

Bug: 207772338
Test: treehugger
Change-Id: I26f9859301275b65bf65357d614044edf1167828
1 file changed