Implement handling of arrow functions in the parser

src/scanner.cc

Index: src/scanner.cc
diff --git a/src/scanner.cc b/src/scanner.cc
index 48bfd33269034fe0f3a423de5ddf7c1bb58cecd7..107f0ec75f3feaa8ff856a0cb036b2353d5f051f 100644
--- a/src/scanner.cc
+++ b/src/scanner.cc
@@ -417,10 +417,12 @@ void Scanner::Scan() {
         break;
 
       case '=':
-        // = == ===
+        // = == === =>
         Advance();
         if (c0_ == '=') {
           token = Select('=', Token::EQ_STRICT, Token::EQ);
+        } else if (c0_ == '>') {
+          token = Select(Token::ARROW);
         } else {
           token = Token::ASSIGN;
         }