Let the cargo_bench_failing_test tolerate col info

[est31]

Needed by rust-lang/rust#42938

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @matklad (or someone else) soon.

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[matklad]

Thanks!

@bors r+

[bors]

📌 Commit 6f34f86 has been approved by matklad

[bors]

⌛ Testing commit 6f34f86 with merge 5bf71ab...

[bors]

☀️ Test successful - status-appveyor, status-travis
Approved by: matklad
Pushing 5bf71ab to master...