Experimental scanner: fix starting positions of tokens.

src/lexer/experimental-scanner.h

Index: src/lexer/experimental-scanner.h
diff --git a/src/lexer/experimental-scanner.h b/src/lexer/experimental-scanner.h
index b85aa770befa19715e420f7d4ef9dfa44b9e1abe..a049e9f8703f0d2d1c05a9e452cdcf45cbe8cefd 100644
--- a/src/lexer/experimental-scanner.h
+++ b/src/lexer/experimental-scanner.h
@@ -302,6 +302,7 @@ class ExperimentalScanner : public ScannerBase {
         last_octal_end_(NULL) {
     ASSERT(source->IsFlat());
     SetBufferBasedOnHandle();
+    current_.beg_pos = current_.end_pos = next_.beg_pos = next_.end_pos = 0;
   }
 
   virtual void Init() {