[bug#65898] Ocaml optional native compiler: it still fails for i686-linux

[Vivien Kraus]

Hi,

The native compiler for ocaml is not always available, especially for
i686-linux. The first step is to get the "best" possible compiler
instead of requiring the native compiler. However, building for i686-
linux still fails. The test suite reports no failure nor error, but it
still fails. What does that mean?

```
Summary:
  2285 tests passed
  592 tests skipped
    0 tests failed
  569 tests not started (parent test skipped or failed)
    0 unexpected errors
  3446 tests considered
make[1]: Leaving directory '/tmp/guix-build-ocaml-5.0.0.drv-
0/source/testsuite'

Test suite failed, dumping logs.
```

Vivien