[clang] [clang][ssaf] Implement JSONFormat (PR #180021)

[Aviral Goel via cfe-commits]

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@@ -29,6 +29,7 @@ class EntityIdTable;
 /// \see EntityIdTable
 class EntityId {
   friend class EntityIdTable;
+  friend class SerializationFormat;
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aviralg wrote:

Yes. With the latest merge against llvm/main, the situation is resolved. Note that we have an explicit method in SerializationFormat.h to create an EntityId since its constructors are private, unlike other framework data structures that have public constructors.

https://github.com/llvm/llvm-project/pull/180021