[Courgette] Using LabelManager to reduce Courgette-apply peak RAM by 25%.

courgette/label_manager.cc

Index: courgette/label_manager.cc
diff --git a/courgette/label_manager.cc b/courgette/label_manager.cc
index a109d8bda9fe9d43877301b2910150650e0ece03..51e0d5de43c945bfb2f7aeb39222586d626b5ce5 100644
--- a/courgette/label_manager.cc
+++ b/courgette/label_manager.cc
@@ -96,17 +96,6 @@ LabelManager::LabelManager() {}
 LabelManager::~LabelManager() {}
 
 // static
-int LabelManager::GetIndexBound(const RVAToLabel& labels_map) {
-  int max_index = -1;
-  for (const auto& rva_and_label : labels_map) {
-    const Label& label = *rva_and_label.second;
-    if (label.index_ != Label::kNoIndex)
-      max_index = std::max(max_index, label.index_);
-  }
-  return max_index + 1;
-}
-
-// static
 int LabelManager::GetLabelIndexBound(const LabelVector& labels) {
   int max_index = -1;
   for (const Label& label : labels) {