[clang] [WIP][Modules] Delay deserialization of preferred_name attribute at r… (PR #122726)

[Ilya Biryukov via cfe-commits]

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@@ -1205,6 +1205,12 @@ class ASTReader
   /// been completed.
   std::deque<PendingDeclContextInfo> PendingDeclContextInfos;
 
+  struct PendingPreferredNameAttribute {
+    uint64_t RecordIdx;
+    Decl *D;
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ilya-biryukov wrote:

Could we use a more descriptive name and/or add a comment explaining why we have this `Decl` here?
`D` looks fine for parameters, but a little too short for a `struct`.

https://github.com/llvm/llvm-project/pull/122726