w_symbol          404 marshal.c          w_symbol(rb_intern(s), arg);
w_symbol          473 marshal.c          w_symbol(id, arg->arg);
w_symbol          490 marshal.c          w_symbol(rb_id_encoding(), arg->arg);
w_symbol          583 marshal.c      	w_symbol(SYM2ID(obj), arg);
w_symbol          754 marshal.c      		    w_symbol(SYM2ID(RARRAY_PTR(mem)[i]), arg);