[clang] [llvm] [LLVM][PassBuilder] Extend the function signature of callback for optimizer pipeline extension point (PR #100953)

[Johannes Doerfert via cfe-commits]

jdoerfert wrote:

Split it, and maybe add the Phase to the rest as well. One commit to just make it consistent and pass the information along.
Second for the AMDGPU stuff.

> @jdoerfert Possibly the issue you saw is that this callback just isn't used by the post-link full LTO pipeline at all? It uses invokeFullLinkTimeOptimizationLastEPCallbacks instead. Maybe with this change it would make sense to remove that one and merge it into the main OptimizerLastEPCallback with the appropriate LTOPhase?

The problem is that the OptimizerLastEPCallback is not called in FullLTO post link, IIRC. So this will alone not solve our issue. However, we still should tell the callbacks what phase we are in, consistently.

https://github.com/llvm/llvm-project/pull/100953