portlib test on CGC failing in CI for ARM64

[pmatos]

https://github.com/racket/racket/runs/1367893779?check_suite_focus=true#step:12:111

[pmatos]

Also: https://github.com/racket/racket/runs/1367893787?check_suite_focus=true#step:12:69

[pmatos]

@mflatt Due you think it's worth it investigating this? I am considering disabling tests in CGC for arm64 and focus on using the hardware more effectively by just testing BC (3m) and CS

[mflatt]

I think it makes sense to disable CGC tests on Arm64, but I will certainly investigate meanwhile.

[pmatos]

Thanks. I will allow a full run before disabling them.

[mflatt]

I think a17516f was relevant for the crash. At least, trying to run the test led me to that problem.

[pmatos]

Right - doesn't seem to be crashing anymore. Thanks.

[pmatos]

Might have spoken too soon - still failing in 145d6c8

There's test failure in cify version: https://github.com/racket/racket/runs/1387018542?check_suite_focus=true#step:12:75
and a segfault in the noncify version: https://github.com/racket/racket/runs/1387018553?check_suite_focus=true#step:12:69

Leaving this open.

[pmatos]

Possibly related to #3284 (same test failure)

[pmatos]

Also #3004