ripper: Preprocess ripper-dispatchable types only

Keep the other types, which not having setter macros for ripper.

ext/ripper/tools/preproc.rb

@@ -59,10 +59,9 @@ def prelude(f, out)
     when /\A%%/
       out << "%%\n"
       return
-    when /\A%token/, /\A} <node>/
-      out << line.sub(/<\w+>/, '<val>')
-    when /\A%type/
-      out << line.sub(/<\w+>/, '<val>')
+    when /\A%token/, /\A%type/, /\A} <node>/
+      # types in %union which have corresponding set_yylval_* macro.
+      out << line.sub(/<(?:node|num|id)>/, '<val>')
     when /^enum lex_state_(?:bits|e) \{/
       lex_state_def = true
       out << line

parse.y

@@ -1627,7 +1627,7 @@ static int looking_at_eol_p(struct parser_params *p);
 %type <id>   f_kwrest f_label f_arg_asgn call_op call_op2 reswords relop dot_or_colon
 %type <id>   p_kwrest p_kwnorest p_any_kwrest p_kw_label
 %type <id>   f_no_kwarg f_any_kwrest args_forward excessed_comma nonlocal_var
- %type <ctxt> lex_ctxt begin_defined k_class k_module /* keep <ctxt> in ripper */
+%type <ctxt> lex_ctxt begin_defined k_class k_module
 %token END_OF_INPUT 0	"end-of-input"
 %token <id> '.'
 /* escaped chars, should be ignored otherwise */