Give FreeBSD 12 tasks on Cirrus a human usable name
Give FreeBSD 12 tasks on Cirrus a human usable name

With this change the name "freebsd-12" will show up in GitHub interface.

[skip ci]

cquinn/ponyc,ponylang/ponyc,sgebbie/ponyc,cquinn/ponyc,sgebbie/ponyc,kulibali/ponyc,sgebbie/ponyc,jemc/ponyc,kulibali/ponyc,ponylang/ponyc,kulibali/ponyc,cquinn/ponyc,dipinhora/ponyc,CausalityLtd/ponyc,jemc/ponyc,sgebbie/ponyc,sgebbie/ponyc,ponylang/ponyc,dipinhora/ponyc,CausalityLtd/ponyc,kulibali/ponyc,dipinhora/ponyc,cquinn/ponyc,jemc/ponyc,CausalityLtd/ponyc