C89 and C99 do not define drand48 so it's not in a strict compile. C89 does not warn about missing function declarations so the test in missing.py did not work. (This leads to confusing behavior where drand48 appears to always return 0.)
I have a stricter test in branch jed/missing-prototype, but it fails because it creates duplicate definitions once the feature test macros are defined. I'm not sure how to resolve this "dialect" issue. We should probably not be creating the missing declarations when they can be obtained via feature test macros.
