Add Solaris support for meson
It did not break anything for my local Linux build. CI had nothign to complain either: https://travis-ci.org/github/Enlightenment/efl/builds/698853314
Personally I do not really see a big benefit for having sun support here, but you are using it and you did the work. Its not to complicated to get added.
I just hope you (or someone else) is using it often enough to be worth the extra work. :-)
Looks good to me, but I would leave the final say here to @bu5hm4n