[clang] [clang] Add test for CWG1807 (PR #77637)

[Vlad Serebrennikov via cfe-commits]

Endilll wrote:

@erichkeane Defect report reads
> The test should also validate the non-catch case! The destruction order is also relevant for the 'try' block's cleanup as well. So there is probably two different 'check' sections here that need to happen.

So I think while both your points are interesting, they are out of scope of the DR.

https://github.com/llvm/llvm-project/pull/77637