[llvm] [InstCombine] Use known bits to simplify mask in foldSelectICmpAnd (PR #128741)

[Yingwei Zheng via llvm-commits]

================
@@ -148,11 +149,13 @@ static Value *foldSelectICmpAnd(SelectInst &Sel, ICmpInst *Cmp,
   } else if (auto Res = decomposeBitTestICmp(Cmp->getOperand(0),
                                              Cmp->getOperand(1), Pred)) {
     assert(ICmpInst::isEquality(Res->Pred) && "Not equality test?");
-    if (!Res->Mask.isPowerOf2())
+    AndMask = Res->Mask;
+    V = Res->X;
+    KnownBits Known = computeKnownBits(V, 0, SQ.getWithInstruction(Cmp));
----------------
dtcxzyw wrote:

```suggestion
    KnownBits Known = computeKnownBits(V, /*Depth=*/0, SQ.getWithInstruction(&Sel));
```


https://github.com/llvm/llvm-project/pull/128741