[AVR] Add final jump to trueMBB

(avr-rust/rust-legacy-fork#46)

Author: gergoerdi

lib/Target/AVR/AVRISelLowering.cpp

@@ -1622,6 +1622,8 @@ AVRTargetLowering::EmitInstrWithCustomInserter(MachineInstr &MI,
   // select.
   trueMBB->splice(trueMBB->begin(), MBB,
                   std::next(MachineBasicBlock::iterator(MI)), MBB->end());
+  if (MBB->succ_begin() != MBB->succ_end())
+      BuildMI(trueMBB, dl, TII.get(AVR::RJMPk)).addMBB(*MBB->succ_begin());
   trueMBB->transferSuccessorsAndUpdatePHIs(MBB);
 
   AVRCC::CondCodes CC = (AVRCC::CondCodes)MI.getOperand(3).getImm();