[llvm] [ValueTracking] Add support for overflow detection functions is `isKnownNonZero` (PR #87701)

[via llvm-commits]

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@@ -166,3 +165,293 @@ A:
 B:
   ret i1 0
 }
+
+declare void @use.i1(i1)
+declare void @use.i8(i1)
+define i1 @extract_value_uadd(i8 %xx, i8 %yy) {
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goldsteinn wrote:

I think you do understand correctly. I think basically all of our extra logic for `isNonZeroAdd` is really dup logic of proving `nuw`.

https://github.com/llvm/llvm-project/pull/87701