Cast as VALUE to suppress type warnings

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@57663 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

parse.y

@@ -786,7 +786,7 @@ static VALUE parser_heredoc_dedent(struct parser_params*,VALUE);
 #define FIXME 0
 
 #else
-#define ID2VAL(id) (id)
+#define ID2VAL(id) ((VALUE)(id))
 #define TOKEN2VAL(t) ID2VAL(t)
 #endif /* RIPPER */