cmake: set CC and CXX compiler variables for all platforms
cmake: set CC and CXX compiler variables for all platforms

https://bugzilla.gnome.org/show_bug.cgi?id=723641

GStreamer/cerbero,nirbheek/cerbero-old,freedesktop-unofficial-mirror/gstreamer__sdk__cerbero,shoreflyer/cerbero,flexVDI/cerbero,OptoFidelity/cerbero,flexVDI/cerbero,sdroege/cerbero,multipath-rtp/cerbero,superdump/cerbero,fluendo/cerbero,sdroege/cerbero,GStreamer/cerbero,brion/cerbero,AlertMe/cerbero,freedesktop-unofficial-mirror/gstreamer__sdk__cerbero,sdroege/cerbero,ramaxlo/cerbero,freedesktop-unofficial-mirror/gstreamer__sdk__cerbero,lubosz/cerbero,fluendo/cerbero,EricssonResearch/cerbero,nzjrs/cerbero,ikonst/cerbero,brion/cerbero,lubosz/cerbero,EricssonResearch/cerbero,fluendo/cerbero,ford-prefect/cerbero,superdump/cerbero,jackjansen/cerbero,fluendo/cerbero,superdump/cerbero,atsushieno/cerbero,EricssonResearch/cerbero,justinjoy/cerbero,atsushieno/cerbero,lubosz/cerbero,nirbheek/cerbero-old,multipath-rtp/cerbero,justinjoy/cerbero,AlertMe/cerbero,freedesktop-unofficial-mirror/gstreamer__cerbero,OptoFidelity/cerbero,nzjrs/cerbero,nirbheek/cerbero,ramaxlo/cerbero,AlertMe/cerbero,sdroege/cerbero,shoreflyer/cerbero,ford-prefect/cerbero,superdump/cerbero,ford-prefect/cerbero,davibe/cerbero,nirbheek/cerbero-old,flexVDI/cerbero,GStreamer/cerbero,GStreamer/cerbero,justinjoy/cerbero,centricular/cerbero,nirbheek/cerbero,justinjoy/cerbero,ramaxlo/cerbero,atsushieno/cerbero,sdroege/cerbero,fluendo/cerbero,ikonst/cerbero,nirbheek/cerbero,OptoFidelity/cerbero,jackjansen/cerbero,flexVDI/cerbero,freedesktop-unofficial-mirror/gstreamer__cerbero,freedesktop-unofficial-mirror/gstreamer__cerbero,brion/cerbero,ikonst/cerbero,freedesktop-unofficial-mirror/gstreamer__sdk__cerbero,lubosz/cerbero,centricular/cerbero,centricular/cerbero,centricular/cerbero,jackjansen/cerbero,centricular/cerbero,davibe/cerbero,shoreflyer/cerbero,shoreflyer/cerbero,brion/cerbero,davibe/cerbero,davibe/cerbero,atsushieno/cerbero,freedesktop-unofficial-mirror/gstreamer__cerbero,EricssonResearch/cerbero,OptoFidelity/cerbero,shoreflyer/cerbero,AlertMe/cerbero,multipath-rtp/cerbero,atsushieno/cerbero,ramaxlo/cerbero,brion/cerbero,EricssonResearch/cerbero,GStreamer/cerbero,nzjrs/cerbero,nzjrs/cerbero,ikonst/cerbero,multipath-rtp/cerbero,AlertMe/cerbero,nzjrs/cerbero,flexVDI/cerbero,nirbheek/cerbero,ford-prefect/cerbero,ramaxlo/cerbero,multipath-rtp/cerbero,ikonst/cerbero,nirbheek/cerbero-old,jackjansen/cerbero