Cygwin: stdio: don't try again to read after EOF

This reverts commit 1f8f7e2d54, "* libc/stdio/refill.c (__srefill):
Try again after EOF on Cygwin."  If EOF is set on a file, the stdio
input functions will now immediately return EOF rather than trying
again to read.  This aligns Cygwin's behavior to that of Linux.

Addresses: https://cygwin.com/pipermail/cygwin/2022-June/251672.html

newlib/libc/stdio/refill.c

@@ -47,11 +47,9 @@ __srefill_r (struct _reent * ptr,
 
   fp->_r = 0;			/* largely a convenience for callers */
 
-#ifndef __CYGWIN__
   /* SysV does not make this test; take it out for compatibility */
   if (fp->_flags & __SEOF)
     return EOF;
-#endif
 
   /* if not already reading, have to be reading and writing */
   if ((fp->_flags & __SRD) == 0)
@@ -115,13 +113,7 @@ __srefill_r (struct _reent * ptr,
 
   fp->_p = fp->_bf._base;
   fp->_r = fp->_read (ptr, fp->_cookie, (char *) fp->_p, fp->_bf._size);
-#ifndef __CYGWIN__
   if (fp->_r <= 0)
-#else
-  if (fp->_r > 0)
-    fp->_flags &= ~__SEOF;
-  else
-#endif
     {
       if (fp->_r == 0)
 	fp->_flags |= __SEOF;

winsup/cygwin/release/3.4.0

@@ -17,6 +17,10 @@ What changed:
   opened in byte mode rather than message mode.
   Addresses: https://cygwin.com/pipermail/cygwin/2021-March/247987.html
 
+- The stdio input functions no longer try again to read after EOF.
+  This aligns Cygwin behavior to that of Linux.
+  Addresses: https://cygwin.com/pipermail/cygwin/2022-June/251672.html
+
 
 Bug Fixes
 ---------

winsup/doc/new-features.xml

@@ -29,6 +29,10 @@ opened in byte mode rather than message mode.
 Handle UDP_SEGMENT and UDP_GRO socket options.
 </para></listitem>
 
+<listitem><para>
+The stdio input functions no longer try again to read after EOF.
+</para></listitem>
+
 </itemizedlist>
 
 </sect2>