Portability fix for glob.h building in FreeBSD ports system.

Portability fix for glob.h building in FreeBSD ports system.

Implement a fix for bug # 2169: too many OSs, even major OSs like Solaris,
don't properly implement SA_RESTART: important system calls like stat() can
still fail when SA_RESTART is set.  So, forget the BROKEN_RESTART config
check and get rid of atomic_stat() and atomic_readdir(), and implement
permanent wrappers for EINTR checking on various system calls (stat(),
fstat(), opendir(), and readdir() so far).