Update partial parser and scanner to be able to skip expressions like "new Map<S, T>()".

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 2dd4d38891b8ceed534189afce0409ad42be88c2..d4fd88e15ff86f01497b75a263f7b8114f67c6b3 100644
--- a/dart/lib/compiler/implementation/scanner/scanner.dart
+++ b/dart/lib/compiler/implementation/scanner/scanner.dart
@@ -341,6 +341,7 @@ class AbstractScanner<T extends SourceString> implements Scanner {
 
   int tokenizeEquals(int next) {
     // = == ===
+    discardOpenLt();
     next = advance();
     if (next === $EQ) {
       return select($EQ, EQ_EQ_EQ_INFO, EQ_EQ_INFO);