symbols: set tag_seen when assigning a type to symbols

* src/reader.h, src/reader.c (tag_seen): Move to...
* src/symtab.h, src/symtab.c: here.
(symbol_type_set): Set it to true.
* src/parse-gram.y: Don't.

src/parse-gram.y

@@ -417,7 +417,6 @@ symbol_declaration:
     }
 | "%type" TAG symbols.1
     {
-      tag_seen = true;
       for (symbol_list *list = $3; list; list = list->next)
         symbol_type_set (list->content.sym, $2, @2);
       symbol_list_free ($3);
@@ -446,7 +445,7 @@ precedence_declarator:
 
 tag.opt:
   %empty { $$ = NULL; }
-| TAG    { $$ = $1; tag_seen = true; }
+| TAG    { $$ = $1; }
 ;
 
 /* Just like symbols.1 but accept INT for the sake of POSIX.  */
@@ -496,7 +495,6 @@ symbol_def:
   TAG
     {
       current_type = $1;
-      tag_seen = true;
     }
 | id int.opt[num] string_as_id.opt[alias]
     {

src/reader.c

@@ -45,9 +45,6 @@ merger_list *merge_functions;
 /* Was %union seen?  */
 bool union_seen = false;
 
-/* Was a tag seen?  */
-bool tag_seen = false;
-
 /* Should rules have a default precedence?  */
 bool default_prec = true;
 

src/reader.h

@@ -69,9 +69,6 @@ extern merger_list *merge_functions;
 /* Was %union seen?  */
 extern bool union_seen;
 
-/* Was a tag seen?  */
-extern bool tag_seen;
-
 /* Should rules have a default precedence?  */
 extern bool default_prec;
 

src/symtab.c

@@ -46,17 +46,14 @@ symbol *accept = NULL;
 symbol *startsymbol = NULL;
 location startsymbol_location;
 
-/*---------------------------.
-| Precedence relation graph. |
-`---------------------------*/
-
+/* Precedence relation graph. */
 static symgraph **prec_nodes;
 
-/*-----------------------------------.
-| Store which associativity is used. |
-`-----------------------------------*/
+/* Store which associativity is used.  */
+static bool *used_assoc = NULL;
+
+bool tag_seen = false;
 
-bool *used_assoc = NULL;
 
 /*--------------------------.
 | Create a new sym_content. |
@@ -334,6 +331,7 @@ symbol_type_set (symbol *sym, uniqstr type_name, location loc)
 {
   if (type_name)
     {
+      tag_seen = true;
       if (sym->content->type_name)
         complain_symbol_redeclared (sym, "%type",
                                     sym->content->type_location, loc);

src/symtab.h

@@ -248,6 +248,8 @@ extern symbol *startsymbol;
 /** The location of the \c \%start declaration.  */
 extern location startsymbol_location;
 
+/** Whether a symbol declared with a type tag.  */
+extern bool tag_seen;
 
 
 /*-------------------.