Only record one in n line endings to save space.

src/objects.h

Index: src/objects.h
diff --git a/src/objects.h b/src/objects.h
index 4ea4cceca50d302a59f010c924a2f590698e1478..2b53430a4376c9da1af6880fa173baf8e1efbae3 100644
--- a/src/objects.h
+++ b/src/objects.h
@@ -6534,6 +6534,11 @@ class Script: public Struct {
   static const int kSourceMappingUrlOffset = kSourceUrlOffset + kPointerSize;
   static const int kSize = kSourceMappingUrlOffset + kPointerSize;
 
+  // Sync with constants in macros.py.
+  static const int kReductionIndex = 0;
+  static const int kNumberOfLinesIndex = 1;
+  static const int kFirstLineEndIndex = 2;
+
  private:
   int GetLineNumberWithArray(int code_pos);