[llvm] [CGSCC] Fix compile time blowup with large RefSCCs (PR #94815)

[Arthur Eubanks via llvm-commits]

aeubanks wrote:

#98213 should fix the assert, let me know if you are still seeing issues. sorry for the trouble (we really need to remove CallGraphUpdater...)

https://github.com/llvm/llvm-project/pull/94815