[llvm] [llvm-exegesis][unittests] Disable SubprocessMemoryTest on big-endian… (PR #102755)

[Rainer Orth via llvm-commits]

rorth wrote:

> There is only one test here that should actually be dependent on endianness (the one marked explicitly).
> 
> I've never run this test on a big-endian system myself to debug, so I can't say for sure, but I would suspect that there is a different issue (the zero value is really suspicious from your test failures)

I see.  I'd rather not try this myself since I've just spent 3 days digging through a large and completely unfamilier part of the code base to fix two failing tests.

> Ultimately though, this test is for functionality that is only enabled on x86_64. I'd rather not carve out x86_64 specifically to prevent people missing this on bringup though.
> 
> I'm not opposed to this patch, but I'd probably prefer a carve out specific to Sparc pending more investigation.

So would it be ok to move the `!(powerpc || s390x || sparc)` check up as in the revised patch?

https://github.com/llvm/llvm-project/pull/102755