[llvm] Remove prof branch weights if switch has 0-1 cases or no branch-weights set in SwitchInstProfUpdateWrapper (PR #163120)

[Mircea Trofin via llvm-commits]

https://github.com/mtrofin commented:

What is the motivation?

Should it set the branch weights to "unknown" instead? Or the idea would be to catch the case where the weights get removed in profcheck?

Do any new tests fail under profcheck w your change?
See https://discourse.llvm.org/t/rfc-profile-information-propagation-unittesting/73595/11

https://github.com/llvm/llvm-project/pull/163120