test: Check HAVE_GETOPT_H

[jschueller]

No description provided.

[stevengj]

I'm worried about the case where the header file getopt.h is missing but we still have getopt in libc.

Probably we should also rename ourgetopt implementation to nlopt_getopt and add #define getopt nlopt_getopt etc. to nlopt-getopt.h

[jschueller]

or check that getopt function is available throught the compiler: check_function_exists(getopt HAVE_GETOPT)

[stevengj]

If the function is available through the compiler (i.e. linking succeeds), but getopt.h is not available, then I think we probably still want to use our own implementation — testopt.c will be using our own header file nlopt-getopt.h in any case, and we would be implicitly assuming that our header file matches the signature of the getopt implementation that the compiler is linking to.

[jschueller]

ok