[llvm] [VPlan] Add hidden `-vplan-print-after-all` option (PR #175839)

[Florian Hahn via llvm-commits]

fhahn wrote:

@eas I reverted the change for now to get the bots back to green: https://github.com/llvm/llvm-project/commit/eabcdb572b00605379a2a18704803bad77ee639c.

Hopefully the logs provide the required info needed to reproduce

https://github.com/llvm/llvm-project/pull/175839