D lang compilers have an option -release (or similar) which turns off
asserts, contracts, and other runtime type checking. This patch wires
that up to the b_ndebug flag.
Fixes#7082
This will copy the file to the build directory without trying to read
it or substitute values into it.
Also do this optimization if the configuration_data() object passed to
the `configuration:` kwarg is empty, and print a warning about it.
See also: https://github.com/mesonbuild/meson/issues/1542
This already reports the location (in a slightly different format), but
using mlog.warning() will make it easier if we want to change the location
format in future.
Xavier Claessens
Dylan Baker
Jussi Pakkanen
Nirbheek Chauhan
Jon Turney