#4058 Regression test smallserpent_op_encrypt fails for ucz80-unsafe-read

[Maarten Brock]

As seen in the snapshots the regression test smallserpent_op_encrypt fails with an invalid instruction for ucz80-unsafe-read, but not for any other target on:

• x86_64-apple-macosx

It tests fine on my local amd64-linux.

Failure: gen/ucz80-unsafe-read/smallserpent/smallserpent_op_encrypt
Invalid instruction: gen/ucz80-unsafe-read/smallserpent/smallserpent_op_encrypt