Add warning if configure_file overwrites output.
Add warning if configure_file overwrites output.

Record the output for each call to configure_file.
If a previous output is overwritten print a warning.

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