I'm not sure how this matters. The order of evaluation is the same, the
BUILD_SET implementation just hashes the evaluated items in a different
order. You can't really rely on that particular order as it's tied
closely to the stack representation CPython uses. I also see no
practical reason -- or even practical *way* -- to abuse the hashing
order. But you have given me an idea on how to improve some of the code
in the BUILD_*_UNPACK opcodes, hmm.