[llvm] [CGP] Consider arguments and ret values in `dupRetToEnableTailCallOpts` (PR #76613)

[Dmitry Vyukov via llvm-commits]

dvyukov wrote:

> Can you provide any performance numbers (real applications, benchmark suite) etc?

What will depend on these numbers? Do you mean that we don't merge this if it's not possible to demonstrate the effect? Obtaining relativistic performance data for smaller improvements is usually very expensive, and not possible to do an improvement less than 0.1%.

https://github.com/llvm/llvm-project/pull/76613