[clang] [APINotes] Refactor APINotesReader to propagate llvm::Error (PR #183812)

[Gábor Horváth via cfe-commits]

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@@ -98,8 +98,11 @@ APINotesManager::loadAPINotes(FileEntryRef APINotesFile) {
 
   // Load the binary form we just compiled.
   auto Reader = APINotesReader::Create(std::move(CompiledBuffer), SwiftVersion);
-  assert(Reader && "Could not load the API notes we just generated?");
-  return Reader;
+  if (!Reader) {
+    llvm::consumeError(Reader.takeError());
+    return nullptr;
+  }
+  return std::move(Reader.get());
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Xazax-hun wrote:

Nit: do we need `std::move` here? I'd expect C++ to try to move the expression that was just returned even without `std::move`.

https://github.com/llvm/llvm-project/pull/183812