[V8] Reland https://codereview.chromium.org/1100993003/

src/scanner.cc

Index: src/scanner.cc
diff --git a/src/scanner.cc b/src/scanner.cc
index aa5ae4a5e93c317dd804d92420b792fdf0707221..04b3dd1353d0030d8b1918755c25c4ea55895257 100644
--- a/src/scanner.cc
+++ b/src/scanner.cc
@@ -225,6 +225,10 @@ static const byte one_char_tokens[] = {
 
 
 Token::Value Scanner::Next() {
+  if (next_.token == Token::EOS) {
+    next_.location.beg_pos = current_.location.beg_pos;
+    next_.location.end_pos = current_.location.end_pos;
+  }
   current_ = next_;
   has_line_terminator_before_next_ = false;
   has_multiline_comment_before_next_ = false;