[llvm] Use thinlto and pgo for x86_64 windows release packaging (PR #71067)

[Pierrick Bouvier via llvm-commits]

pbo-linaro wrote:

Oh yes, I missed that. So memory usage might be more a problem when linking (with thinLTO) all binaries. Better to not enable this for now.

No problem to do it in another PR. Indeed, all the architectures (x86, x64, arm64) could benefit from PGO. 

https://github.com/llvm/llvm-project/pull/71067