[llvm-branch-commits] [lsan] Add debug option to "deflake" leaks (PR #112037)

[Vitaly Buka via llvm-branch-commits]

https://github.com/vitalybuka created https://github.com/llvm/llvm-project/pull/112037

There are hard to debug leaks which look like
false.

In general, repeating leak checking should not
affect set of leaks significantly, especial
`at_exit` leak checking.

But if we see significant discrepancy, it may give
us a clue for investigation.