[llvm] [NFC][StructurizeCFG] Add a test that can crash StructurizeCFG pass (PR #126087)

[Shilei Tian via llvm-commits]

shiltian wrote:

> Can you also open a tracking issue and add a reference to the test (like in the file name)

Done.

https://github.com/llvm/llvm-project/pull/126087