Don't check for bounds in find/position on lists with safety 0.
Check for :start in find/position on lists.
Github actions: run on ubuntu-24.04 which has a newer sbcl.
Transform (= small-int float) and not just (= float small-int).
github actions: use a more recent sbcl host.
Compile on netbsd arm64 with sb-core-compression option.
x86-64: don't get confused by negative constants in logior/signed.
arm64: add a vop for (logior signed-word unsigned-word)