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
Fortran: check for undeclared variables by forcing implicit none everywhere
C/C++: check for unused parameters and return types
removed unused variables from test cases
ci: do missing return and unused arg check with Github Actions