[scanner] Reuse SkipSingleLineComment in SkipSourceURLComment

Change-Id: Ie8109300ce134f3f9d0c1619f1375c29af2c8fa6
Reviewed-on: https://chromium-review.googlesource.com/c/1494758Reviewed-by: Leszek Swirski <leszeks@chromium.org>
Commit-Queue: Toon Verwaest <verwaest@chromium.org>
Cr-Commit-Position: refs/heads/master@{#59967}

src/parsing/scanner.cc

@@ -277,11 +277,10 @@ Token::Value Scanner::SkipSingleLineComment() {
 
 Token::Value Scanner::SkipSourceURLComment() {
   TryToParseSourceURLComment();
-  while (c0_ != kEndOfInput && !unibrow::IsLineTerminator(c0_)) {
-    Advance();
+  if (unibrow::IsLineTerminator(c0_) || c0_ == kEndOfInput) {
+    return Token::WHITESPACE;
   }
-
-  return Token::WHITESPACE;
+  return SkipSingleLineComment();
 }
 
 void Scanner::TryToParseSourceURLComment() {