[llvm] Port CodeGenPrepare to new pass manager (and BasicBlockSectionsProfil… (PR #75380)

[Simon Pilgrim via llvm-commits]

RKSimon wrote:

@paperchalice @nickleus27 I've reverted this (and #77054) as they were breaking expensive checks builds: https://lab.llvm.org/buildbot/#/builders/104 - please can you take a look?

https://github.com/llvm/llvm-project/pull/75380