Move some cross file parsing validition to MachineInfo
Move some cross file parsing validition to MachineInfo

This is a domain-specific validation not tied to the surface syntax, so
it belongs here in the pipeline.

becm/meson,pexip/meson,mesonbuild/meson,becm/meson,MathieuDuponchelle/meson,mesonbuild/meson,jpakkane/meson,mesonbuild/meson,QuLogic/meson,pexip/meson,pexip/meson,QuLogic/meson,MathieuDuponchelle/meson,jpakkane/meson,pexip/meson,mesonbuild/meson,MathieuDuponchelle/meson,becm/meson,pexip/meson,mesonbuild/meson,pexip/meson,becm/meson,mesonbuild/meson,jpakkane/meson,becm/meson,pexip/meson,pexip/meson,becm/meson,QuLogic/meson,MathieuDuponchelle/meson,MathieuDuponchelle/meson,jpakkane/meson,jpakkane/meson,becm/meson,QuLogic/meson,becm/meson,QuLogic/meson,jpakkane/meson,pexip/meson,MathieuDuponchelle/meson,MathieuDuponchelle/meson,pexip/meson,jpakkane/meson,QuLogic/meson,mesonbuild/meson,jpakkane/meson,MathieuDuponchelle/meson,QuLogic/meson,mesonbuild/meson,QuLogic/meson,MathieuDuponchelle/meson,jpakkane/meson,mesonbuild/meson,QuLogic/meson,becm/meson,becm/meson,mesonbuild/meson