if (VM.VerifyAssertions) VM.assert(inst.getOpcode() == IR_PROLOGUE_opcode);
if (VM.VerifyAssertions) VM._assert(inst.getOpcode() == IR_PROLOGUE_opcode);
  private void insertEndPrologue() {    OPT_Instruction inst = ir.firstInstructionInCodeOrder().getNext();    if (VM.VerifyAssertions) VM.assert(inst.getOpcode() == IR_PROLOGUE_opcode);    inst.insertBefore(Empty.create(IR_ENDPROLOGUE));    inst.remove();  }