[llvm] [InlineCost] Enable the cost benefit analysis for Sample PGO (PR #66457)

[via llvm-commits]

alexfh wrote:

We see a ~1.5% increase in a binary size after this patch. This can push some of our large binaries over certain limits. While I appreciate the potential performance improvements, I also wonder, if we have a way to revert to the old behavior should this be necessary in some cases?

https://github.com/llvm/llvm-project/pull/66457