Teach ModuleDescriptor about basic local exports

src/modules.h

Index: src/modules.h
diff --git a/src/modules.h b/src/modules.h
index ac04e47c4d76c7d9179b6097d72d410a552ed5e6..b7f5d19abc4c104f14aa2f9dec5760ab5880c700 100644
--- a/src/modules.h
+++ b/src/modules.h
@@ -28,7 +28,8 @@ class ModuleDescriptor : public ZoneObject {
 
   // Add a name to the list of exports. If it already exists, or this descriptor
   // is frozen, that's an error.
-  void Add(const AstRawString* name, Zone* zone, bool* ok);
+  void AddLocalExport(const AstRawString* export_name,
+                      const AstRawString* local_name, Zone* zone, bool* ok);
 
   // Do not allow any further refinements, directly or through unification.
   void Freeze() { frozen_ = true; }
@@ -67,10 +68,14 @@ class ModuleDescriptor : public ZoneObject {
   class Iterator {
    public:
     bool done() const { return entry_ == NULL; }
-    const AstRawString* name() const {
+    const AstRawString* export_name() const {
       DCHECK(!done());
       return static_cast<const AstRawString*>(entry_->key);
     }
+    const AstRawString* local_name() const {
+      DCHECK(!done());
+      return static_cast<const AstRawString*>(entry_->value);
+    }
     void Advance() { entry_ = exports_->Next(entry_); }
 
    private: