Apply the same changes as in yacc.c. Now yySymbol and yysymbol_type_t
are aliases. We will remove the former later, to avoid cluttering
this commit.
* data/skeletons/glr.c: Use b4_declare_symbol_enum.
Use YYSYMBOL_YYEOF etc. where appropriate.
(YYUNDEFTOK, YYTERROR): Remove.
(YYTRANSLATE, yySymbol, yyexpected_tokens, yysyntax_error_arguments):
Adjust.
(yy_accessing_symbol): New.
Use it where appropriate.