RFR: 8229283: StringLatin1 should consistently use CharacterDataLatin1.instance when applicable

[Brent Christian]

Hi Claes,

Some observations:

  394 int u1 = CharacterDataLatin1.instance.toUpperCase(c1);
  395 int u2 = CharacterDataLatin1.instance.toUpperCase(c2);

Changing u1 & u2 from char -> int, L399 now calls toLowerCase(int) 
instead of toLowerCase(char).  Should be fine, though.  Speaking of:

  399 if (Character.toLowerCase(u1) == Character.toLowerCase(u2)) {

Should/could this line also be changed?

  421 if (Character.toLowerCase(u1) == Character.toLowerCase(u2)) {

Similarly, maybe Character.toLowerCase(u1) -> 
CharacterDataLatin1.instance.toUpperCase(u1) ?


  477 lowerChar = CharacterDataLatin1.instance.toLowerCase(srcChar);
  ...

Initially I was nervous about the lower/upper case changes, but I've 
convinced myself that StringLatin1 handles these cases correctly.

FWIW, the changes from Character.toUpperCaseEx() (e.g. L512) now skip:
         assert isValidCodePoint(codePoint);

and changes from Character.toUpperCaseCharArray() (e.g. L562) now skip:
         assert isBmpCodePoint(codePoint);

in Character.java.

Thanks,
-Brent