Add a minimal reproducer for the ICE in #6179

[Y-Nak]

This PR is an auxiliary PR for #6179, just add a minimal reproducer for the ICE discussed in #6179.
See #6179 for more details.

changelog: none

[rust-highfive]

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[flip1995]

NIT: Can you put this test in a separate file in the crashes/ dir? Normally we name them ice-<#PR/Issue>.rs and they usually don't have any output.

[Y-Nak]

Changes: Move the reproducer in crashes/.

[flip1995]

@bors r+

Thanks!

[bors]

📌 Commit 87109bb has been approved by flip1995

[bors]

⌛ Testing commit 87109bb with merge 5f611ce...

[bors]

☀️ Test successful - checks-action_dev_test, checks-action_remark_test, checks-action_test
Approved by: flip1995
Pushing 5f611ce to master...