Process: Increase FD_SETSIZE on Cygwin

The Single UNIX (R) Specification, Version 2 defines "FD_SETSIZE", but
does not specify the effects if it's (re)defined by an application.

Cygwin's newlib headers document that FD_SETSIZE may be defined
by the user [1] and should be >= NOFILE. [2]  Setting it to 16384
uses a value from Cygwin's poll() implementation. [3]

[1]: http://cygwin.com/cgi-bin/cvsweb.cgi/src/newlib/libc/include/sys/types.h?cvsroot=src
[2]: http://cygwin.com/cgi-bin/cvsweb.cgi/src/winsup/cygwin/include/sys/param.h?cvsroot=src
[3]: http://cygwin.com/cgi-bin/cvsweb.cgi/src/winsup/cygwin/poll.cc?cvsroot=src

Change-Id: Idc43fc28a398979da1e9289e1080a9fc1090c605

ProcessUNIX.c

@@ -47,6 +47,12 @@ do.
 
 */
 
+#if defined(__CYGWIN__)
+/* Increase the file descriptor limit for select() before including
+   related system headers. (Default: 64) */
+# define FD_SETSIZE 16384
+#endif
+
 #include <stddef.h>    /* ptrdiff_t */
 #include <stdio.h>     /* snprintf */
 #include <stdlib.h>    /* malloc, free */