[icu-design] API proposal: change signature for RBBI::checkDictionary for 64-bit

[Deborah G. <gol...@ap...>]

Since RuleBasedBreakIterator::checkDictionary will become protected  
in ICU4C 3.8, it would be a good idea to fix it to handle 64-bit  
offsets, so that the implementation of RBBI can eventually handle 64  
bit offsets. I propose changing the signature from:

     int32_t checkDictionary(int32_t startPos, int32_t endPos, UBool  
reverse);

to

     int64_t checkDictionary(int64_t startPos, int64_t endPos, UBool  
reverse);

Deborah