if (len >= 0) bcIndex += len; else          skipSpecialInstruction(opcode);
if (len >= 0) { bcIndex += len; } else { skipSpecialInstruction(opcode); }
  public final void skipInstruction() {    if (VM.VerifyAssertions) VM._assert(bcIndex <= bcLength);    int len = JBC_length[opcode] - 1;    if (wide) len += len;    if (len >= 0) bcIndex += len;    else          skipSpecialInstruction(opcode);  }