[llvm] [X86][NFC] Moved/Updated llvm.set.rounding testcases (PR #155434)

[Evgenii Kudriashov via llvm-commits]

https://github.com/e-kud commented:

Failures look unrelated:
```
lldb-api :: lang/cpp/libcxx-internals-recognizer/TestLibcxxInternalsRecognizer.py
LLVM :: CodeGen/AMDGPU/llvm.amdgcn.rcp.bf16.ll
```
@JaydeepChauhan14 maybe update the branch?

https://github.com/llvm/llvm-project/pull/155434