Fix bug with multiple directives in the preparser

src/parsing/preparser.h

Index: src/parsing/preparser.h
diff --git a/src/parsing/preparser.h b/src/parsing/preparser.h
index b99d9852d19f82974333fe74ff9b7f3fa0def7b8..b98abf86081a173107c2d819236f73db8d81e4cd 100644
--- a/src/parsing/preparser.h
+++ b/src/parsing/preparser.h
@@ -376,7 +376,8 @@ class PreParserStatement {
   }
 
   bool IsStringLiteral() {
-    return code_ == kStringLiteralExpressionStatement;
+    return code_ == kStringLiteralExpressionStatement
+        || IsUseStrictLiteral() || IsUseStrongLiteral();
   }
 
   bool IsUseStrictLiteral() {