[llvm] GlobalISel: Use G_UADDE when narrowing G_UMULH (PR #97194)

[Thorsten Schütt via llvm-commits]

tschuett wrote:

For G_UADDE, we could try to combine it down to add + constant 1: https://github.com/llvm/llvm-project/blob/66d86a63e7f10905fd3e6104cebceeb53851ff1d/llvm/lib/CodeGen/GlobalISel/CombinerHelper.cpp#L7293

```
(sum, carryout) = G_UADDE (x, y, carryin)
```
If x + y always overflows, ...

https://github.com/llvm/llvm-project/pull/97194