errors: indent missing action code semicolon warning

Also, remove a duplicate #define.

* src/scan-code.l (SC_RULE_ACTION): Here.
* tests/actions.at: Adjust.

src/scan-code.l

@@ -220,12 +220,16 @@ ref      -?[0-9]+|{id}|"["{id}"]"|"$"
     /* As an undocumented Bison extension, append ';' before the last
        brace in braced code, so that the user code can omit trailing
        ';'.  But do not append ';' if emulating Yacc, since Yacc does
-       not append one.  */
+       not append one.  This is deprecated since release 2.4.1.  */
     if (outer_brace && !yacc_flag && language_prio == default_prio
         && skeleton_prio == default_prio && need_semicolon && ! in_cpp)
       {
-        warn_at (*loc, _("a ';' might be needed at the end of action code"));
+        unsigned int indent = 0;
-        warn_at (*loc, _("future versions of Bison will not add the ';'"));
+        warn_at_indent (*loc, &indent,
+                       _("a ';' might be needed at the end of action code"));
+        indent += SUB_INDENT;
+        warn_at_indent (*loc, &indent,
+                       _("future versions of Bison will not add the ';'"));
         obstack_1grow (&obstack_for_string, ';');
       }
 
@@ -489,9 +493,6 @@ show_sub_messages (const char* cp, bool explicit_bracketing,
    points to LHS ($$) of the current rule or midrule. */
 #define LHS_REF (INT_MIN + 1)
 
-/* Sub-messages indent. */
-#define SUB_INDENT (4)
-
 /* Parse named or positional reference. In case of positional
    references, can return negative values for $-n "deep" stack
    accesses. */

tests/actions.at

@@ -1586,41 +1586,41 @@ AT_BISON_OPTION_POPDEFS
 
 AT_BISON_CHECK([[-o input.c input.y]], [0], [],
 [[input.y:8.48: warning: a ';' might be needed at the end of action code
-input.y:8.48: warning: future versions of Bison will not add the ';'
+input.y:8.48:     future versions of Bison will not add the ';'
 input.y:9.48: warning: a ';' might be needed at the end of action code
-input.y:9.48: warning: future versions of Bison will not add the ';'
+input.y:9.48:     future versions of Bison will not add the ';'
 input.y:10.48: warning: a ';' might be needed at the end of action code
-input.y:10.48: warning: future versions of Bison will not add the ';'
+input.y:10.48:     future versions of Bison will not add the ';'
 input.y:11.48: warning: a ';' might be needed at the end of action code
-input.y:11.48: warning: future versions of Bison will not add the ';'
+input.y:11.48:     future versions of Bison will not add the ';'
 input.y:12.48: warning: a ';' might be needed at the end of action code
-input.y:12.48: warning: future versions of Bison will not add the ';'
+input.y:12.48:     future versions of Bison will not add the ';'
 input.y:13.48: warning: a ';' might be needed at the end of action code
-input.y:13.48: warning: future versions of Bison will not add the ';'
+input.y:13.48:     future versions of Bison will not add the ';'
 input.y:20.1: warning: a ';' might be needed at the end of action code
-input.y:20.1: warning: future versions of Bison will not add the ';'
+input.y:20.1:     future versions of Bison will not add the ';'
 input.y:21.1: warning: a ';' might be needed at the end of action code
-input.y:21.1: warning: future versions of Bison will not add the ';'
+input.y:21.1:     future versions of Bison will not add the ';'
 input.y:22.1: warning: a ';' might be needed at the end of action code
-input.y:22.1: warning: future versions of Bison will not add the ';'
+input.y:22.1:     future versions of Bison will not add the ';'
 input.y:23.1: warning: a ';' might be needed at the end of action code
-input.y:23.1: warning: future versions of Bison will not add the ';'
+input.y:23.1:     future versions of Bison will not add the ';'
 input.y:24.1: warning: a ';' might be needed at the end of action code
-input.y:24.1: warning: future versions of Bison will not add the ';'
+input.y:24.1:     future versions of Bison will not add the ';'
 input.y:25.1: warning: a ';' might be needed at the end of action code
-input.y:25.1: warning: future versions of Bison will not add the ';'
+input.y:25.1:     future versions of Bison will not add the ';'
 input.y:31.1: warning: a ';' might be needed at the end of action code
-input.y:31.1: warning: future versions of Bison will not add the ';'
+input.y:31.1:     future versions of Bison will not add the ';'
 input.y:32.1: warning: a ';' might be needed at the end of action code
-input.y:32.1: warning: future versions of Bison will not add the ';'
+input.y:32.1:     future versions of Bison will not add the ';'
 input.y:33.1: warning: a ';' might be needed at the end of action code
-input.y:33.1: warning: future versions of Bison will not add the ';'
+input.y:33.1:     future versions of Bison will not add the ';'
 input.y:34.1: warning: a ';' might be needed at the end of action code
-input.y:34.1: warning: future versions of Bison will not add the ';'
+input.y:34.1:     future versions of Bison will not add the ';'
 input.y:35.1: warning: a ';' might be needed at the end of action code
-input.y:35.1: warning: future versions of Bison will not add the ';'
+input.y:35.1:     future versions of Bison will not add the ';'
 input.y:36.1: warning: a ';' might be needed at the end of action code
-input.y:36.1: warning: future versions of Bison will not add the ';'
+input.y:36.1:     future versions of Bison will not add the ';'
 ]])
 
 AT_MATCHES_CHECK([input.c], [[/\* TEST:N:2 \*/ \}$]],       [[3]])