[llvm] [KnownBits] Add KnownBits::add and KnownBits::sub helper wrappers. (PR #99468)

[via llvm-commits]

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@@ -329,6 +329,19 @@ struct KnownBits {
   static KnownBits computeForSubBorrow(const KnownBits &LHS, KnownBits RHS,
                                        const KnownBits &Borrow);
 
+  /// Compute knownbits resulting from addition of LHS and RHS.
+  /// NSW and NUW flags are assumed to be false.
+  static KnownBits add(const KnownBits& LHS, const KnownBits& RHS) {
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goldsteinn wrote:

\*cough\* and we shouldn't \*cough\*

https://github.com/llvm/llvm-project/pull/99468