libxfs: compile with a C++ compiler

Apparently C++ compilers don't like the implicit void* casts that go on
in the system headers.  Compile a dummy program with the C++ compiler to
make sure this works.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Tested-by: Sam James <sam@gentoo.org>
Reviewed-by: Sam James <sam@gentoo.org>
6 files changed