Linkme is broken on the x86_64-pc-windows-gnu
target (see https://github.com/dtolnay/linkme/issues/25)
so static entities are now called entity declarations and must be
created manually.
Hashbrown's HashMap & HashSet is faster than std's. I
guess this is because std (which uses hashbrown) does
not enable hashbrown's default-hasher flag and instead
uses a slower hasher.
