if (VM.VerifyAssertions) VM._assert(false);
  Extent(int offset) {      if (VM.VerifyAssertions && VM.runningVM) VM._assert(VM.NOT_REACHED);  // call site should have been hijacked by magic in compiler    //-#if RVM_FOR_32_ADDR    value = offset;    //-#else    if (VM.VerifyAssertions) VM._assert(false);    //-#endif  }