This will be needed for the Unicode Standard's Default Case Algorithm.
Generate the field as an enumeration rather than a string for easier
comparison.
This adds a SpecialCasing structure to the generated UnicodeData.h/cpp
files. This structure contains casing rules for code points which have
non-1-to-1 upper-to-lower case code point mappings. Further, these rules
may be limited to specific locales or other context.
The Unicode standard publishes the Unicode Character Database (UCD) with
information about every code point, such as each code point's upper case
mapping. LibUnicode exists to download and parse UCD files at build time
and to provide accessors to that data.
As a start, LibUnicode includes upper- and lower-case code point
converters.