[clang] [clang-repl] Move the produced temporary files in wasm in a temp folder. (PR #175508)

[Anutosh Bhat via cfe-commits]

anutosh491 wrote:

1) All tests pass with the above diff 
2) Let's say I compare master vs the above diff. I try 3 inputs and then for the 4th input, I paste out the content

i) Master : We expose the generated files

<img width="600" height="800" alt="image" src="https://github.com/user-attachments/assets/512314fe-2aa5-4d04-8a21-1f30999a0672" />


ii) This commit : The unique dir isn't mounted in the vfs

<img width="600" height="800" alt="image" src="https://github.com/user-attachments/assets/5187c79e-c10d-4aa4-841d-98e73678b869" />

I think that's exactly what we were looking for here !

https://github.com/llvm/llvm-project/pull/175508