This allows us to remove all the add_subdirectory calls from the top
level CMakeLists.txt that referred to targets linking LagomCore.
Segregating the host tools and Serenity targets helps us get to a place
where the main Serenity build can simply use a CMake toolchain file
rather than swapping all the compiler/sysroot variables after building
host libraries and tools.
This commit is preemptive to upcoming commits which add more subtags to
the CLDR generator. Rather than generating a giant HashMap containing
all data, generate more (smaller) Array-based tables. This mimics the
UCD generator. This also allows simpler lookups at runtime since we can
generate index-based lookups into the smaller tables rather easily.
Without this change, adding the remaining locale subtags would result
in the generation and compilation of UnicodeLocale.cpp taking about 30s
on my machine. With this change, it takes about half that. Additionally,
the size of the generated file reduces by about 1.5MB.
The UCD set of data contained a very small subset of all locales just to
handle some special casing rules. This enumeration will be needed within
the CLDR generator as well. So rather than duplicate the enum, remove it
from the UCD generator in favor of the full list of locales known by the
CLDR generator.
The Unicode standard publishes a database known as the Common Locale
Data Repository (CLDR). This is a massive set of data from which anyone
implementing Unicode's Technical Standard #35 may generate their
implementation: https://www.unicode.org/reports/tr35/
This commit updates LibUnicode to download the compressed database and
extract a small subset. That subset is used to generate a list of
available locales and the territories (AKA regions) associated with each
locale.