audio/sidplay2: Unbreak on FreeBSD 12.0
- While here also add license information
checking for working sidplay2 library and headers... /usr/local/lib, /usr/local/include
configure: error:
sidplay2 build test failed with found library and header files.
Please check your installation!
In file included from conftest.cc:27:
...
/usr/include/stdlib.h:97:17: error: declaration of 'exit' has a different language linkage
_Noreturn void exit(int);
^
conftest.cc:11:6: note: previous declaration is here
void exit (int);