[modules] Basic support of exports

src/ast/scopes.h

Index: src/ast/scopes.h
diff --git a/src/ast/scopes.h b/src/ast/scopes.h
index 0c10633e02fdc387cd7e238dafe9b98839b82744..1bec87f6636aeb1857d0217350b14c77adf907b9 100644
--- a/src/ast/scopes.h
+++ b/src/ast/scopes.h
@@ -371,6 +371,9 @@ class Scope: public ZoneObject {
   // 'this' is bound, and what determines the function kind.
   DeclarationScope* GetReceiverScope();
 
+  // Find the module scope, assuming there is one.
+  ModuleScope* GetModuleScope();
+
   // Analyze() must have been called once to create the ScopeInfo.
   Handle<ScopeInfo> scope_info() {
     DCHECK(!scope_info_.is_null());
@@ -677,9 +680,9 @@ class DeclarationScope : public Scope {
   }
 
   // Parameters. The left-most parameter has index 0.
-  // Only valid for function scopes.
+  // Only valid for function and module scopes.
   Variable* parameter(int index) const {
-    DCHECK(is_function_scope());
+    DCHECK(is_function_scope() || is_module_scope());
     return params_[index];
   }