Declare 'this' as DYNAMIC_GLOBAL on the script_scope

src/parsing/parser.cc

Index: src/parsing/parser.cc
diff --git a/src/parsing/parser.cc b/src/parsing/parser.cc
index 59d31f5a73514fd5c8a7f98d8e4be9146f8f433f..b294e98a4799e70c3c6220a89f87bc90e53e9600 100644
--- a/src/parsing/parser.cc
+++ b/src/parsing/parser.cc
@@ -998,6 +998,12 @@ FunctionLiteral* Parser::DoParseProgram(ParseInfo* info) {
   FunctionLiteral* result = NULL;
   {
     Scope* outer = original_scope_;
+    // If there's a chance that there's a reference to global 'this', predeclare
+    // it as a dynamic global on the script scope.
+    if (outer->GetDeclarationScope()->is_script_scope()) {
+      info->script_scope()->DeclareDynamicGlobal(
+          ast_value_factory()->this_string(), Variable::THIS);
+    }
     DCHECK(outer);
     if (info->is_eval()) {
       if (!outer->is_script_scope() || is_strict(info->language_mode())) {