This does require hacking up the test pretty badly, since we need to not
ever pass GCC these invalid values. But it's preferable to writing
another project test I think.
Co-Authored-by: Nirbheek Chauhan <nirbheek@centricular.com>
This means that arguments set via `add_global_arguments`,
`add_project_arguments` and by either the `-Dc_args` or `CFLAGS` are
applied to bindgen as well. This can be important when, among other
things, #defines are set via these mechanisms.
Fixes: #12065
This has a couple of advantages over rolling it by hand:
1. it correctly handles include_directories objects, which is always
handy
2. it correctly generates a depfile for you, which makes it more
reliable
3. it requires less typing