[RFC] Deprecate dbx mode

[Tom Tromey <tromey@adacore.com>]

GDB has a dbx emulation mode that adds a few aliases and helper
commands.  This mode is barely documented and is very superficial
besides.  I suspect it is rarely used, and I would like to propose
deprecating it for GDB 12, and then removing it in GDB 13.
---
 gdb/NEWS   | 2 ++
 gdb/main.c | 3 +++
 2 files changed, 5 insertions(+)

diff --git a/gdb/NEWS b/gdb/NEWS
index dc2cac1871b..0b75a4a50bd 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -3,6 +3,8 @@
 
 *** Changes since GDB 11
 
+* DBX mode is deprecated, and will be removed in GDB 13
+
 * Improved C++ template support
 
   GDB now treats functions/types involving C++ templates like it does function
diff --git a/gdb/main.c b/gdb/main.c
index 8f944d86545..73fdff25018 100644
--- a/gdb/main.c
+++ b/gdb/main.c
@@ -1028,6 +1028,9 @@ captured_main_1 (struct captured_main_args *context)
       }
   }
 
+  if (dbx_commands)
+    warning (_("--dbx mode is deprecated and will be removed"));
+
   save_original_signals_state (quiet);
 
   /* Try to set up an alternate signal stack for SIGSEGV handlers.  */
-- 
2.34.1