Remove >>> and >>>= from scanner.

dart/lib/compiler/implementation/scanner/scanner.dart

Index: dart/lib/compiler/implementation/scanner/scanner.dart
diff --git a/dart/lib/compiler/implementation/scanner/scanner.dart b/dart/lib/compiler/implementation/scanner/scanner.dart
index 3f05e8b552cbe9a0474a4ee00164c76d078ad1a5..c6bd646a8915de97e973c6933c32068591a43b28 100644
--- a/dart/lib/compiler/implementation/scanner/scanner.dart
+++ b/dart/lib/compiler/implementation/scanner/scanner.dart
@@ -431,15 +431,6 @@ class AbstractScanner<T extends SourceString> implements Scanner {
       if ($EQ === next) {
         appendPrecedenceToken(GT_GT_EQ_INFO);
         return advance();
-      } else if ($GT === next) {
-        next = advance();
-        if (next === $EQ) {
-          appendPrecedenceToken(GT_GT_GT_EQ_INFO);
-          return advance();
-        } else {
-          appendGtGtGt(GT_GT_GT_INFO, ">>>");
-          return next;
-        }
       } else {
         appendGtGt(GT_GT_INFO, ">>");
         return next;