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 revert a part of #7020 because it was using gir_inc_dirs
before it is set. Properly fix typelib_includes instead that was working
only when g-i is a pkgconfig dependency.
MesonDep1 doesn't use symbols from MesonDep2, but uses the MesonDep2
structure definition (so it only needs the header). This means only
generate_gir needs a dependency on MesonDep2 and shared_library doesn't.
This was broken earlier.
MesonSample uses symbols from MesonDep1 and MesonDep2, so both the
library and the gir get a dependency on MesonDep1, and on MesonDep2
(transitively). The transitive dependency was broken earlier.