[CodeGen] Assert that EmittedDeferredDecls is empty

[Hahnfeld]

Summary

Its contents are transferred into DeferredDecls in Release(), so it
should be empty in moveLazyEmissionStates(). This matches the code
downstream in Cling.

[v.g.vassilev]

LGTM!

clang/lib/CodeGen/CodeGenModule.cpp

 }
 
 void CodeGenModule::moveLazyEmissionStates(CodeGenModule *NewBuilder) {
   assert(DeferredDeclsToEmit.empty() &&
          "Should have emitted all decls deferred to emit.");
   assert(NewBuilder->DeferredDecls.empty() &&
          "Newly created module should not have deferred decls");
   NewBuilder->DeferredDecls = std::move(DeferredDecls);
+  assert(EmittedDeferredDecls.empty() &&
+         "Still have (unmerged) EmittedDeferredDecls deferred decls");
 
   assert(NewBuilder->DeferredVTables.empty() &&
          "Newly created module should not have deferred vtables");
   NewBuilder->DeferredVTables = std::move(DeferredVTables);
 
   assert(NewBuilder->MangledDeclNames.empty() &&
          "Newly created module should not have mangled decl names");
   assert(NewBuilder->Manglings.empty() &&
          "Newly created module should not have manglings");
   NewBuilder->Manglings = std::move(Manglings);
 
   NewBuilder->WeakRefReferences = std::move(WeakRefReferences);
 
   NewBuilder->TBAA = std::move(TBAA);
 
-  assert(NewBuilder->EmittedDeferredDecls.empty() &&
-         "Still have (unmerged) EmittedDeferredDecls deferred decls");
-
-  NewBuilder->EmittedDeferredDecls = std::move(EmittedDeferredDecls);
-
   NewBuilder->ABI->MangleCtx = std::move(ABI->MangleCtx);
 }