[llvm] [PseudoProbe] Fix cleanup for pseudo probe after annotation (PR #119660)

[Haohai Wen via llvm-commits]

HaohaiWen wrote:

> The flag was used to avoid probe intrinsic hindering optimizations, so discriminator value etc wasn't important for that purpose. Curious what are you using this flag for?

.llvm.pseudo_probe_desc and discriminator will create .pseudo_probe and .pseudo_probe_desc sections which would increase the binary size of second round sampling PGO build.
Those discriminators and .llvm.pseudo_probe_desc is useless after sample profile loader, so I think they can be removed safely.

https://github.com/llvm/llvm-project/pull/119660