[lldb][Type Completionb] Don't register decls as imported if candidate definition is not found

Author: Michael137

lldb/source/Plugins/ExpressionParser/Clang/ClangASTImporter.cpp

@@ -1210,15 +1210,14 @@ ClangASTImporter::ASTImporterDelegate::ImportImpl(Decl *From) {
     DeclContext::lookup_result lr = dc->lookup(*dn_or_err);
     for (clang::Decl *candidate : lr) {
       if (candidate->getKind() == From->getKind()) {
-        RegisterImportedDecl(From, candidate);
-
-        // If we're dealing with redecl chains. We want to find the definition,
+        // If we're dealing with redecl chains, we want to find the definition,
         // so skip if the decl is actually just a forwad decl.
         if (TypeSystemClang::UseRedeclCompletion())
           if (auto *tag_decl = llvm::dyn_cast<TagDecl>(candidate);
               !tag_decl || !tag_decl->getDefinition())
             continue;
 
+        RegisterImportedDecl(From, candidate);
         m_decls_to_ignore.insert(candidate);
         return candidate;
       }