: void *ruby_xrealloc(void *ptr, long size) 
    ֤ͤΰ̣ realloc() Ʊ
    Ƥ˼ԤȤ
    GC ԤǤʤȤ NoMemoryError  raise 롣
    Ĥޤꤳδؿ֤֤ͤȤϾ˳ƤƤ롣

