`std.Io.tty.Config.detect` may be an expensive check (e.g. involving
syscalls), and doing it every time we need to print isn't really
necessary; under normal usage, we can compute the value once and cache
it for the whole program's execution. Since anyone outputting to stderr
may reasonably want this information (in fact they are very likely to),
it makes sense to cache it and return it from `lockStderrWriter`. Call
sites who do not need it will experience no significant overhead, and
can just ignore the TTY config with a `const w, _` destructure.
This removes the two original implementations in favour of the single
generic one based on the Algorithm type. Previously we had three, very
similar implementations which was somewhat confusing when knowing what
one should actually be used.
The previous polynomials all have equivalent variants available when
using the Algorithm type.
This flips things around such that std/hash/crc.zig is generated
by the catalog-based generation tool, and the real code that used
to be in that file is moved out to std/hash/crc/impl.zig. The
generated tests are moved to std/hash/crc/test.zig. By going this
route, we eliminate the need for usingnamespace without changing
anything for callers of these interfaces. The Crc32 tests are
simply added to the fixed part of the generated output and
compactified a bit.
This was the second-to-last usage of usingnamespace left in std.
