Extend the "common/include order" test to ensure that the build
directory is preferred over the source directory. For example,
when using `configure_file()`, the resulting file should be
preferred over a file with the same name in the source directory.
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
At the same time, also fix the order in which compile arguments are
added. Detailed comments have been added concerning the priority and
order of the arguments.
Also adds a unit test and an integration test for the same.