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

[via llvm-commits]

zmodem wrote:

Apologies for the late reply; I got distracted by other things.

> how portable is the profile information across builds?

It _can_ work across targets, but e.g. if the function names from the profile and the current build don't match because of mangling, those functions will not benefit from the profile info.

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