Update copyright year in version message for gdb, gdbserver and gdbreplay

gdb/ChangeLog:

        * top.c (print_gdb_version): Update copyright year.

gdbserver/ChangeLog:

        * server.cc (gdbserver_version): Update copyright year.
        * gdbreplay.cc (gdbreplay_version): Likewise.

gdb/ChangeLog

@@ -1,3 +1,7 @@
+2021-01-01  Joel Brobecker  <brobecker@adacore.com>
+
+	* top.c (print_gdb_version): Update copyright year.
+
 2021-01-01  Joel Brobecker  <brobecker@adacore.com>
 
 	* config/djgpp/fnchange.lst: Add entry for gdb/ChangeLog-2020.

gdb/top.c

@@ -1409,7 +1409,7 @@ print_gdb_version (struct ui_file *stream, bool interactive)
   /* Second line is a copyright notice.  */
 
   fprintf_filtered (stream,
-		    "Copyright (C) 2020 Free Software Foundation, Inc.\n");
+		    "Copyright (C) 2021 Free Software Foundation, Inc.\n");
 
   /* Following the copyright is a brief statement that the program is
      free software, that users are free to copy and change it on

gdbserver/ChangeLog

@@ -1,3 +1,8 @@
+2021-01-01  Joel Brobecker  <brobecker@adacore.com>
+
+	* server.cc (gdbserver_version): Update copyright year.
+	* gdbreplay.cc (gdbreplay_version): Likewise.
+
 2020-12-16  Luis Machado  <luis.machado@linaro.org>
 
 	* linux-aarch64-low.cc (address_significant): New function.

gdbserver/gdbreplay.cc

@@ -442,7 +442,7 @@ static void
 gdbreplay_version (void)
 {
   printf ("GNU gdbreplay %s%s\n"
-	  "Copyright (C) 2020 Free Software Foundation, Inc.\n"
+	  "Copyright (C) 2021 Free Software Foundation, Inc.\n"
 	  "gdbreplay is free software, covered by "
 	  "the GNU General Public License.\n"
 	  "This gdbreplay was configured as \"%s\"\n",

gdbserver/server.cc

@@ -3321,7 +3321,7 @@ static void
 gdbserver_version (void)
 {
   printf ("GNU gdbserver %s%s\n"
-	  "Copyright (C) 2020 Free Software Foundation, Inc.\n"
+	  "Copyright (C) 2021 Free Software Foundation, Inc.\n"
 	  "gdbserver is free software, covered by the "
 	  "GNU General Public License.\n"
 	  "This gdbserver was configured as \"%s\"\n",