make some Environment methods protected
make some Environment methods protected

they're really not public methods, they'r only meant to be called from
the initializer. Let's mark them as such.

pexip/meson,mesonbuild/meson,QuLogic/meson,pexip/meson,pexip/meson,QuLogic/meson,jpakkane/meson,mesonbuild/meson,jpakkane/meson,pexip/meson,mesonbuild/meson,QuLogic/meson,mesonbuild/meson,mesonbuild/meson,jpakkane/meson,jpakkane/meson,mesonbuild/meson,QuLogic/meson,jpakkane/meson,mesonbuild/meson,pexip/meson,jpakkane/meson,pexip/meson,jpakkane/meson,pexip/meson,jpakkane/meson,QuLogic/meson,QuLogic/meson,mesonbuild/meson,jpakkane/meson,mesonbuild/meson,pexip/meson,QuLogic/meson,mesonbuild/meson,QuLogic/meson,QuLogic/meson,pexip/meson,pexip/meson