[clang] [APINotes] Add Where.Object selectors for C++ methods (PR #216148)

[Gábor Horváth via cfe-commits]

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@@ -158,6 +158,32 @@ class APINotesWriter::Implementation {
     return *Key;
   }
 
+  FunctionTableKey getFunctionKey(uint32_t ParentContextID, StringRef Name,
+                                  const FunctionSelector &Selector) {
+    std::optional<FunctionTableKey> Key;
+    auto GetIdentifier = [this](StringRef S) -> std::optional<IdentifierID> {
+      return getIdentifier(S);
+    };
+    if (Selector.Parameters) {
+      if (Selector.Object)
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Xazax-hun wrote:

This branch almost makes me think if it would be simpler if these functions always took an optional Object and/or parameters and had a default empty optional argument. 

https://github.com/llvm/llvm-project/pull/216148