[DAGCombiner] `visitFREEZE()`: fix cycle breaking

Depending on the particular DAG, we might either create a `freeze`,
or not. And only in the former case, the cycle would be formed.
It would be nicer to have `ReplaceAllUsesOfValueWithIf()`,
like we have in IR, but we don't have that.

Fixes https://github.com/llvm/llvm-project/issues/59677