[clang] [clang-repl] [test] Make an XFAIL more precise (PR #70991)

[Paul T Robinson via cfe-commits]

pogo59 wrote:

FTR, the "Worker" tab on that buildbot page will point you to the maintainer. But tagging me is also fine in general.
I'm unable to repro the problem locally because my local build doesn't seem to include clang-repl.exe, so the whole clang/test/Interpreter directory is Unsupported. Is there some cmake parameter to enable JIT?
In the meantime, tagging @dyung 

https://github.com/llvm/llvm-project/pull/70991