Add parsing for ambient declarations

src/parsing/preparser.h

Index: src/parsing/preparser.h
diff --git a/src/parsing/preparser.h b/src/parsing/preparser.h
index 5ceb6c8b7df00db914b883fcd4e2ab012de04791..988e03b2cf6a813f457d52534e4eba779120e65e 100644
--- a/src/parsing/preparser.h
+++ b/src/parsing/preparser.h
@@ -1219,7 +1219,7 @@ class PreParserTraits {
   PreParserExpression ParseClassLiteral(PreParserIdentifier name,
                                         Scanner::Location class_name_location,
                                         bool name_is_strict_reserved, int pos,
-                                        bool* ok);
+                                        bool ambient, bool* ok);
 
   PreParserExpressionList PrepareSpreadArguments(PreParserExpressionList list) {
     return list;
@@ -1358,17 +1358,17 @@ class PreParser : public ParserBase<PreParserTraits> {
   Statement ParseSubStatement(AllowLabelledFunctionStatement allow_function,
                               bool* ok);
   Statement ParseScopedStatement(bool legacy, bool* ok);
-  Statement ParseFunctionDeclaration(bool* ok);
-  Statement ParseClassDeclaration(bool* ok);
+  Statement ParseFunctionDeclaration(bool ambient, bool* ok);
+  Statement ParseClassDeclaration(bool ambient, bool* ok);
   Statement ParseBlock(bool* ok);
   Statement ParseVariableStatement(VariableDeclarationContext var_context,
-                                   bool* ok);
+                                   bool ambient, bool* ok);
   Statement ParseVariableDeclarations(VariableDeclarationContext var_context,
                                       int* num_decl, bool* is_lexical,
                                       bool* is_binding_pattern,
                                       Scanner::Location* first_initializer_loc,
                                       Scanner::Location* bindings_loc,
-                                      bool* ok);
+                                      bool ambient, bool* ok);
   Statement ParseExpressionOrLabelledStatement(
       AllowLabelledFunctionStatement allow_function, bool* ok);
   Statement ParseIfStatement(bool* ok);
@@ -1408,7 +1408,7 @@ class PreParser : public ParserBase<PreParserTraits> {
   PreParserExpression ParseClassLiteral(PreParserIdentifier name,
                                         Scanner::Location class_name_location,
                                         bool name_is_strict_reserved, int pos,
-                                        bool* ok);
+                                        bool ambient, bool* ok);
 };