introduce -Wdeprecated

GCC seems to be using "deprecated" consistently over "obsoleted", so
use -Wdeprecated rather than -Wobsolete.

* src/complain.h (warnings): Add Wdeprecated.
* src/complain.c (warnings_print_categories): Adjust.
* src/getargs.c: Likewise.
* doc/bison.texi: Document it.

* src/scan-code.l: Use this category for the trailing ';' support.
* tests/actions.at: Adjust expected output.

src/complain.c

@@ -29,7 +29,8 @@
 #include "files.h"
 #include "getargs.h"
 
-warnings warnings_flag = Wconflicts_sr | Wconflicts_rr | Wother;
+warnings warnings_flag =
+  Wconflicts_sr | Wconflicts_rr | Wdeprecated  | Wother;
 
 bool complaint_issued;
 static unsigned *indent_ptr = 0;
@@ -45,6 +46,7 @@ warnings_print_categories (warnings warn_flags)
           "yacc",
           "conflicts-sr",
           "conflicts-rr",
+          "deprecated",
           "other"
         };
 

src/complain.h

@@ -32,7 +32,8 @@ typedef enum
     Wyacc             = 1 << 1,  /**< POSIXME.  */
     Wconflicts_sr     = 1 << 2,  /**< S/R conflicts.  */
     Wconflicts_rr     = 1 << 3,  /**< R/R conflicts.  */
-    Wother            = 1 << 4,  /**< All other warnings.  */
+    Wdeprecated       = 1 << 4,  /**< Obsolete constructs.  */
+    Wother            = 1 << 5,  /**< All other warnings.  */
 
     Werror            = 1 << 10, /**< Warnings are treated as errors.  */
     complaint         = 1 << 11, /**< All complaints.  */

src/getargs.c

@@ -218,6 +218,7 @@ static const char * const warnings_args[] =
   "yacc            - incompatibilities with POSIX Yacc",
   "conflicts-sr    - S/R conflicts",
   "conflicts-rr    - R/R conflicts",
+  "deprecated      - obsolete constructs",
   "other           - all other warnings",
   "all             - all of the above",
   "error           - warnings are errors",
@@ -231,6 +232,7 @@ static const int warnings_types[] =
   Wyacc,
   Wconflicts_sr,
   Wconflicts_rr,
+  Wdeprecated,
   Wother,
   Wall,
   Werror

src/scan-code.l

@@ -225,9 +225,9 @@ ref      -?[0-9]+|{id}|"["{id}"]"|"$"
     if (outer_brace && !yacc_flag && language_prio == default_prio
         && skeleton_prio == default_prio && need_semicolon && ! in_cpp)
       {
-        complain_at (*loc, Wother,
+        complain_at (*loc, Wdeprecated,
                      _("a ';' might be needed at the end of action code"));
-        complain_at (*loc, Wother,
+        complain_at (*loc, Wdeprecated,
                      _("future versions of Bison will not add the ';'"));
         obstack_1grow (&obstack_for_string, ';');
       }