[llvm] [Attributor]: allow more than one offset for a pass through user in AAPointerInfo (PR #94416)

[Johannes Doerfert via llvm-commits]

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@@ -1607,11 +1607,20 @@ ChangeStatus AAPointerInfoFloating::updateImpl(Attributor &A) {
     //
     // The RHS is a reference that may be invalidated by an insertion caused by
     // the LHS. So we ensure that the side-effect of the LHS happens first.
+
+    if (!OffsetInfoMap.contains(Usr)) {
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jdoerfert wrote:

Why this check? Can't we merge into an empty value?

https://github.com/llvm/llvm-project/pull/94416