6933322: Add methods highSurrogate(), lowSurrogate() to class Character
Summary: Add public variants of methods Surrogate.high, Surrogate.low
Reviewed-by: okutsu, sherman
Contributed-by: Ulf Zibis <ulf.zibis@gmx.de>
6934270: Remove javac warnings from Character.java
Summary: Use generics and conform to coding style
Reviewed-by: sherman
Contributed-by: Ulf Zibis <ulf.zibis@gmx.de>