[Bug target/116086] RISC-V: Hash mismatch with vectorized 557.xz_r at zvl128b and LMUL=m2

[patrick at rivosinc dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=116086

--- Comment #8 from Patrick O'Neill <patrick at rivosinc dot com> ---
(In reply to Robin Dapp from comment #6)
> Ah, thanks for reducing.  I didn't get much further with cvise yesterday. 
> What were your settings for it?

I used the normal settings (just --timeout to fail hangs early) for
creduce/cvise but tried a few manual tricks like pulling the arrays into
globals so they'd be zero-initialized and pulling out struct fields, deleting
function args, and unrolling arrays into individual vars. Most of the magic was
on creduce's side with help from ubsan/asan.