Intermittent crash in make test

[LiberalArtist]

Quoting @mflatt in #808 (comment):

Meanwhile, the test failure appears to be a crash in the test related to signal handling. I have seen this on occasion, and I suspect an issue with the test, but I didn't figure it out the last time I tried.

I've hit this problem several more times while building 10.0.0 and 9.9.9-pre-release.23 (from Racket 8.12). I don't really know what's going on, but I thought I should open this to track it.

[LiberalArtist]

I've hit the issue with make test-some in addition to make test. IIRC, every time it's happened the last line has included eval=interpret, so I'll try make test-some-fast next.

[LiberalArtist]

I've had make test-some-fast fail, too (last line: -------- o=3 cp0=t cp0 --------), so I think I just need to skip tests for now.