[llvm] Introduce CounterExpressionBuilder::replace(C, Map) (PR #112698)

[NAKAMURA Takumi via llvm-commits]

chapuni wrote:

@ornata I don't think it valuable to test. Or could I abandon it and sink it to #112730 ?

I prefer NFC changes may be committed in advance but it prevents your preference "write test anyways".

https://github.com/llvm/llvm-project/pull/112698