[clang] [clang-tools-extra] [llvm] [CGProfile] Use callee's PGO name when caller->callee is an indirect call. (PR #78610)

[Mingming Liu via cfe-commits]

minglotus-6 wrote:

>  I'm missing the full context behind this patch, but code seems reasonable

Thanks for the review! This patch is supposed to be self-contained as a fix, although it's spotted when I worked on relevant larger efforts ([type profiling](https://discourse.llvm.org/t/rfc-dynamic-type-profiling-and-optimizations-in-llvm/74600) and [better call graph](https://discourse.llvm.org/t/rfc-for-better-call-graph-sort-build-a-more-complete-call-graph-by-adding-more-indirect-call-edges/74029)) when trying to figure out how PGO names of functions work in the pipeline.

https://github.com/llvm/llvm-project/pull/78610