Experimental scanner fix: recognize one byte strings inside utf16 files.

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 fea691a2246be1f6ac6ca5c9f8cd065c12da41eb..7f81565e652db36b77f22747d093b1c36ab9a7b5 100644
--- a/src/lexer/experimental-scanner.h
+++ b/src/lexer/experimental-scanner.h
@@ -163,6 +163,7 @@ class ScannerBase {
     return current_literal_->length;
   }
 
+  // This should be is_onebyte or is_latin1; it doesn't mean ASCII for real.
   bool is_literal_ascii() {
     if (!current_literal_->Valid(current_.beg_pos)) {
       FillLiteral(current_, current_literal_);