Add unique storage for parsed CalendarPattern structures to ensure only
one copy of each structure is generated.
This doesn't have any impact on libunicode.so with the current generated
data. Rather, this prevents the amount of generated data from needlessly
growing astronomically once date-time patterns are fully parsed. There
will be 173,459 patterns parsed, of which only 22,495 (about 12%) are
unique. This change will save a few MB, and will also help compilation
times.
Currently, there's only a handful of entries in these arrays, so it is
not a huge deal to generate them inline with the struct that holds them.
But they will each soon contain a few hundred entries. Generate them out
of line for easier viewing in the generated code.
This is not a calendar supported by ECMA-402, so let's not waste space
with its data.
Further, don't generate "gregorian" as a valid Unicode locale extension
keyword. It's an invalid type identifier, thus cannot be used in locales
such as "en-u-ca-gregorian".
Unlike most data in the CLDR, hour cycles are not stored on a per-locale
basis. Instead, they are keyed by a string that is usually a region, but
sometimes is a locale. Therefore, given a locale, to determine the hour
cycles for that locale, we:
1. Check if the locale itself is assigned hour cycles.
2. If the locale has a region, check if that region is assigned hour
cycles.
3. Otherwise, maximize that locale, and if the maximized locale has
a region, check if that region is assigned hour cycles.
4. If the above all fail, fallback to the "001" region.
Further, each locale's default hour cycle is the first assigned hour
cycle.
Similar to number formatting, the data for date-time formatting will be
located in its own generated file. This extracts the cldr-dates package
from the CLDR and sets up the generator plumbing to create the date-time
data files.
