p5-json 2.08 Add xs variant to depend on p5-json-xs

[borys@…]

There is a new port for p5-json-xs in ticket #15082.

p5-json will automatically use JSON::XS if it is already installed, but this patch adds an xs variant that will add a dependency to ensure that p5-json-xs is installed.

I would suggest making it part of default_variants.

[borys@…]

Patch to add xs variant to p5-json port

[narf_tm@…]

Patch added to changeset [40020].