#4033 serpent test failures for z80-related ports

[Philipp Klaus Krause]

Creating random-753392452706332246 based on ucz80 with additional options: --nolospre --nogenconstprop --nolabelopt --no-peep --nosidechannels --max-allocs-per-node 128 
Running random-753392452706332246 regression tests
Summary for 'random-753392452706332246': 2 abnormal stops ( 1 invalid instructions, ), 0 failures, 36377 tests, 6251 test cases, 0 bytes, 4015774868 ticks
   Invalid instruction: serpent_op_decrypt
   abnormal stop: serpent_op_decrypt
   abnormal stop: serpent_op_encrypt

Creating random-5227915840794816095 based on ucr800 with additional options: --opt-code-size --nolospre --nogenconstprop --nolabelopt --no-peep --nosidechannels --max-allocs-per-node 128 
Running random-5227915840794816095 regression tests
Summary for 'random-5227915840794816095': 1 abnormal stops ( 1 invalid instructions, ), 0 failures, 36228 tests, 6252 test cases, 0 bytes, 318222468 ticks
   Invalid instruction: serpent_op_decrypt
   abnormal stop: serpent_op_decrypt

Creating random-9583503406857600663 based on ucz80 with additional options: --opt-code-size --nolospre --nogenconstprop --nolabelopt --noloopreverse --no-peep --max-allocs-per-node 128 
Running random-9583503406857600663 regression tests
Summary for 'random-9583503406857600663': 1 abnormal stops ( 1 invalid instructions, ), 4 failures, 36381 tests, 6252 test cases, 0 bytes, 1626270794 ticks
   Failure: serpent_op_decrypt
   Invalid instruction: serpent_op_encrypt
   abnormal stop: serpent_op_encrypt