[llvm] [Attributor] Change allocation size and load/store offsets using AAPointerInfo for Alloca instructions (PR #72029)

[Shilei Tian via llvm-commits]

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@@ -6181,11 +6278,53 @@ struct AAPointerInfo : public AbstractAttribute {
       }
     }
 
+    // Merge two access paths into one.
+    void mergeAccessPaths(const AccessPathSetTy *AccessPathsNew) const {
+      for (auto *Path : *AccessPathsNew)
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shiltian wrote:

It looks like all the uses of `AccessPaths` assumes `AccessPaths` is never `nullptr`. If it is the case, use a `&` instead, or at least assert non-`nullptr`?

https://github.com/llvm/llvm-project/pull/72029