[Bug 4510] New: Check for arpa/nameser.h fails with -ansi

[Wine Bugs]

http://bugs.winehq.org/show_bug.cgi?id=4510

Summary: Check for arpa/nameser.h fails with -ansi
           Product: Wine
           Version: CVS
          Platform: PC
        OS/Version: Linux
            Status: UNCONFIRMED
          Severity: minor
          Priority: P2
         Component: wine-misc
        AssignedTo: [e-mail]
        ReportedBy: [e-mail]

With CFLAGS="-ansi", the configure check for arpa/nameser.h fails to compile.

This is caused by nameser.h relying on BSD libc features to compile, which
aren't enabled when -ansi is defined.

One possible fix is to make sure _BSD_SOURCE is defined in CFLAGS by configure
prior to the check.