IDSET_ATTRSET_FOR_SYNTAX  313 symbol.c           return rb_enc_symname_type(name, len, enc, IDSET_ATTRSET_FOR_SYNTAX) != -1;
IDSET_ATTRSET_FOR_SYNTAX 1132 symbol.c           return rb_str_symname_type(name, IDSET_ATTRSET_FOR_SYNTAX) == -1;