while (true) {
    probe_name.resize(probe_prefix_size);
    // TODO(jpienaar): Subtract one so that the initial suffix is 0 instead
    // of 1.
    // TODO(jpienaar): Switch to radix 36 and update tests.
    llvm::APInt(32, val++).toString(probe_name, /*Radix=*/10, /*Signed=*/false);
    if (IsUnique(probe_name)) {
      // Insert/find if prefix with appended number is unique.
      auto probe_name_it = name_to_count_.try_emplace(probe_name, 1);