Auto merge of #115128 - davidtwco:re-enable-debuginfo-test, r=wesleywiser

tests: re-enable pretty-std-collections on macOS

Fixes #78665.

I made some small modifications to this test so that it would pass for me locally (though I was only able to test using lldb without built-in Rust support, but that seems to be the mode in which it would fail). I ran it a few hundred times with stage one and stage two to see if I could re-produce the spurious failures that were being reported in #78665 and couldn't. From the discussion in #78665, it seemed like this was related to Xcode versions and could be reproduced locally fairly easily. It's been a couple years since this was disabled so a lot has changed. If this starts failing spuriously again then we can disable it and I can look into that.

r? `@wesleywiser` (discussed in wg-debugging's triage meeting)

Author: bors