[scanner] Advance rather than setting c0_ to ' ' after skipping multiline comments

Change-Id: I62ddddf64d4de79765469e883295e246a18d7f84
Reviewed-on: https://chromium-review.googlesource.com/1177749
Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#55172}

src/parsing/scanner.cc

@@ -508,11 +508,8 @@ Token::Value Scanner::SkipMultiLineComment() {
 
     while (V8_UNLIKELY(c0_ == '*')) {
       Advance();
-      // If we have reached the end of the multi-line comment, we
-      // consume the '/' and insert a whitespace. This way all
-      // multi-line comments are treated as whitespace.
       if (c0_ == '/') {
-        c0_ = ' ';
+        Advance();
         return Token::WHITESPACE;
       }
     }