When compiled using clang, an ambiguity error is detected between
`class AK::Time` aliased to `::Time` and the `struct ::Time` provided
in `GenerateTimeZoneData.cpp`. Solve this by moving most of the code in
an anonymous namespace.
The IANA Time Zone Database contains data needed, at least, for various
JavaScript objects. This adds plumbing for a parser and code generator
for this data. The generated data will be made available by LibTimeZone,
much like how UCD and CLDR data is available through LibUnicode.