define SEEK_CUR in unistd.h and fcntl.h

[Bruno Haible]

So far, the three macros SEEK_CUR, SEEK_SET, SEEK_END are defined only in
<stdio.h> on mingw. But mingw wants them to be visible also in <unistd.h>
and <fcntl.h>. This fixes it in the gnulib substitutes.

2007-04-25  Bruno Haible  <address@hidden>

        * lib/unistd_.h: Include <stdio.h> if needed to get the SEEK_* macros.

*** lib/unistd_.h       19 Feb 2007 02:24:42 -0000      1.4
--- lib/unistd_.h       25 Apr 2007 06:44:43 -0000
***************
*** 22,27 ****
--- 22,32 ----
  # include @ABSOLUTE_UNISTD_H@
  #endif
  
+ /* mingw doesn't define the SEEK_* macros in <unistd.h>.  */
+ #if !(defined SEEK_CUR && defined SEEK_END && defined SEEK_SET)
+ # include <stdio.h>
+ #endif
+ 
  
  /* The definition of GL_LINK_WARNING is copied here.  */