build: Use GNOME_COMPILE_WARNINGS
build: Use GNOME_COMPILE_WARNINGS

So we reuse the standard -Werror set of minimal code quality warnings.

GNOME/at-spi2-core,Distrotech/atk,GNOME/at-spi2-core,Distrotech/atk,GNOME/at-spi2-core,Distrotech/atk