[llvm-branch-commits] [NFCI][sanitizers][metadata] Exctract create{Unlikely, Likely}BranchWeights (PR #89464)

[Vitaly Buka via llvm-branch-commits]

https://github.com/vitalybuka created https://github.com/llvm/llvm-project/pull/89464

We have a lot of repeated code with random constants.
Particular values are not important, the one just needs to be
bigger then another.

UR_NONTAKEN_WEIGHT is selected as it's the most common one.