[clang] [Sema][NFC] Move two misplaced uninit tests to clang/test/SemaCXX (PR #128013)

[Donát Nagy via cfe-commits]

NagyDonat wrote:

> I wonder if we should rename the directory to something like `clang/test/StaticAnalyzer` to avoid confusion in the future.

I also considered renaming the directory to `clang/test/StaticAnalyzer` and I would definitely support this idea if it doesn't cause too many difficulties in the maintenance of downstream forks.

https://github.com/llvm/llvm-project/pull/128013