Now that we have most of core free of shadowing, we can enable the
warning as an error to catch anything that may be remaining and also
eliminate this class of logic bug entirely.
While a map is an OK way to do lookups (and usually recommended in most
cases), this is a map that lives for the entire duration of the program
and only deallocates its contents when the program terminates.
Given the total size of the map is quite small, we can simply use a
std::array of pairs and utilize std::find_if to perform the same
behavior without loss of performance.
This eliminates a static constructor and places the data into the
read-only segment.
While we're at it, we can also handle malformed inputs instead of
directly dereferencing the resulting iterator.