Implement stub emulation of `readlink' for MS-DOS.

 src/msdos.c (readlink) [DJGPP < 2.04]: New stub function.
 src/msdos.h: (readlink) [DJGPP < 2.04]: Declare prototype.

diff --cc src/ChangeLog
index f371049,3288a79..a7c9d4c
--- 1/src/ChangeLog
--- 2/src/ChangeLog
+++ b/src/ChangeLog
@@@ -1,40 -1,9 +1,44 @@@
  2011-02-27  Eli Zaretskii  <eliz@gnu.org>
  
+       * msdos.c (readlink) [DJGPP < 2.04]: New stub function.
+ 
+       * msdos.h: (readlink) [DJGPP < 2.04]: Declare prototype.
+ 
 +      * w32.c (symlink, readlink): New stub functions.
 +
 +2011-02-27  Paul Eggert  <eggert@cs.ucla.edu>
 +
 +      * scroll.c (CHECK_BOUNDS): #define only if GLYPH_DEBUG.
 +      This avoids a gcc warning in some configurations.
 +
 +      * frame.c (x_set_screen_gamma): Rename local to avoid shadowing.
 +
 +      * frame.h: Avoid gcc -Wmissing-prototypes diagnostics.
 +      (set_menu_bar_lines, x_get_resource_string): New decls.
 +      * msdos.c (set_menu_bar_lines): Omit decl.
 +
 +      * dispextern.h (struct glyph): Make u.img_id int, not unsigned.
 +      It's always given int values and used as an int.  This suppresses
 +      a gcc "comparison of unsigned expression >= 0" warning in some
 +      configurations.
 +
 +      * dispnew.c: Rename locals to avoid shadowing.
 +      (update_text_area, scrolling_window, update_frame_1): Rename locals.
 +
 +2011-02-26  Paul Eggert  <eggert@cs.ucla.edu>
 +
 +      * dispnew.c: Fix problems uncovered by gcc -Wstrict-prototypes.
 +      (copy_glyph_row_contents): Remove; not used.
 +      (frame_row_to_window, check_current_matrix_flags):
 +      (window_change_signal): Now static, since they're not used elsewhere.
 +      (check_current_matrix_flags): Surround with "#if 0", since its
 +      only use is in a comment.  Maybe both the comment and the "#if 0"
 +      stuff should be removed?
 +
 +      * dispnew.c: Fix problem uncovered by gcc -Wunused-variable.
 +      (adjust_frame_glyphs_for_window_redisplay): Make 'w' local to the
 +      contexts that actually need it.
 +
  2011-02-26  Eli Zaretskii  <eliz@gnu.org>
  
        * s/msdos.h (HAVE_LSTAT): Define for DJGPP >= 2.04.

diff --cc src/msdos.c
Simple merge