[llvm] [memprof] Add another constructor to IndexedAllocationInfo (NFC) (PR #116684)

[Kazu Hirata via llvm-commits]

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@@ -354,10 +354,15 @@ struct IndexedAllocationInfo {
   PortableMemInfoBlock Info;
 
   IndexedAllocationInfo() = default;
+  // This constructor is soft deprecated.  It will be removed once we remove all
+  // users of the CallStack field.
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kazutakahirata wrote:

We cannot quite put `LLVM_DEPRECATED` yet as that would break `-Werror` builds.

https://github.com/llvm/llvm-project/pull/116684