Compiling files in `makesrna` as C code is often a bit annoying when converting
other files to C++ (#103343). That's because one often had to introduce additional
C wrappers.
The goal of this patch is to support compiling rna files as C++ code. This mostly
required changes in `makesrna.c` to make the generated code compatible with C
and C++. The cmake code had to change a bit as well because we need to pass
different compiler options for C++ code to avoid some warnings.
This commit also converts a few rna files to C++ already, although that is mostly
just for testing. The rest of the files are expected to be converted after this patch
is merged.
It's possible, even likely, that `makesrna.c` has to change a little bit more to
support C++, but that is hard to know without converting all files first.
Co-authored-by: Lukas Tönne <lukas@blender.org>
Co-authored-by: Ray Molenkamp <github@lazydodo.com>
Pull Request: https://projects.blender.org/blender/blender/pulls/108290
d154ebfa83