Only works on StandaloneToolExecutor, crashes happen when running
AllTUsExecutors with multithreads (I believe it is because
ClangTidyContext is not threadsafe).
// Restrict thread to 1. ./bin/clang-tidy -executor=all-TUs -filter=".*/extra/*" -checks="-*,readability-braces-around-statements" -execute-concurrency=1 -export-fixes="/tmp/fixes.yaml" .
is this deduplication, or the other place (or both? and if yes why at two places?)