Investigate BIKE failures on x86

[SWilson4]

Enabling BIKE on x86 builds leads to test failures, so we don't do it. However, the upstream documentation states that BIKE is supported for x86. It would be nice to figure out what's going on.

See also: #1443

[baentsch]

Thanks for doing #1679: Just approved.

IMO the upstream use of the term "x86" is just (the computer scientist's equivalent of) "slang", really meaning "x86_64": Those of us remembering that the term originally meant a 32bit platform are dying out. Also they explicitly reference Intel Xeon and a 64 bit compiler:

The package was compiled and tested with clang (version 10.0.0) in 64-bit mode, on a Linux (Ubuntu 20.04) on Intel Xeon (x86) and Graviton 2 (ARM) processors.

Admittedly the following statement is pretty broad:

The x86 tests are done with Intel SDE which can emulate any Intel CPU.

but doesn't completely rule out my understanding: The Intel SDE may be able to emulate any Intel CPU, but the statement does not go so far as to say that tests for any Intel CPU have actually been done.

Asking @dkostic @drucker-nir for input as to what is really meant in the documentation: Has BIKE been tested to run on any Intel CPU or really "just" x64?