Correctly parse line ends for debugging.

src/scanner.h

Index: src/scanner.h
diff --git a/src/scanner.h b/src/scanner.h
index 6e668fd4921ca23e7dbbcd1755404c8269c20bd7..8537c5308c9f73e8dbf2f5f97e8188f195d531cc 100644
--- a/src/scanner.h
+++ b/src/scanner.h
@@ -121,6 +121,12 @@ class UnicodeCache {
   bool IsIdentifierStart(unibrow::uchar c) { return kIsIdentifierStart.get(c); }
   bool IsIdentifierPart(unibrow::uchar c) { return kIsIdentifierPart.get(c); }
   bool IsLineTerminator(unibrow::uchar c) { return kIsLineTerminator.get(c); }
+  bool IsLineTerminatorSequence(unibrow::uchar c, unibrow::uchar next) {
+    if (!IsLineTerminator(c)) return false;
+    if (c == 0x000d && next == 0x000a) return false;  // CR with following LF.
+    return true;
+  }
+
   bool IsWhiteSpace(unibrow::uchar c) { return kIsWhiteSpace.get(c); }
   bool IsWhiteSpaceOrLineTerminator(unibrow::uchar c) {
     return kIsWhiteSpaceOrLineTerminator.get(c);