[llvm] [Knowbits] Make nuw and nsw support in computeForAddSub optimal (PR #83382)

[Matt Arsenault via llvm-commits]

================
@@ -443,7 +593,7 @@ KnownBits KnownBits::abs(bool IntMinIsPoison) const {
       Tmp.One.setBit(countMinTrailingZeros());
 
     KnownAbs = computeForAddSub(
-        /*Add*/ false, IntMinIsPoison,
+        /*Add*/ false, IntMinIsPoison, /*NUW*/ false,
----------------
arsenm wrote:

```suggestion
        /*Add=*/ false, IntMinIsPoison, /*NUW=*/ false,
```

https://github.com/llvm/llvm-project/pull/83382