Unfortunately this means we lose use of the convenient name `gen`, so
this includes a handful of renaming.
We can't increase the edition for `libm` yet due to MSRV, but we can
enable `unsafe_op_in_unsafe_fn` to help make that change smoother in the
future.
When there is a panic in an extensive test, tracing down where it came
from can be difficult since no information is provides (messeges are
e.g. "attempted to subtract with overflow"). Resolve this by calling the
functions within `panic::catch_unwind`, printing the input, and
continuing.
We need someplace to collect known failures, previous regressions, edge
cases that are difficult to construct from generics, and similar.
Introduce this here.
