Collect list of requested modules in ModuleDescriptor while parsing

src/modules.h

Index: src/modules.h
diff --git a/src/modules.h b/src/modules.h
index 7dd7e26716bbbdab086ba1ecb064f3773d5afe2c..33afd6128d39efeddae014f49f31bee47ea4c7f3 100644
--- a/src/modules.h
+++ b/src/modules.h
@@ -20,7 +20,7 @@ class ModuleDescriptor : public ZoneObject {
   // Factory methods.
 
   static ModuleDescriptor* New(Zone* zone) {
-    return new (zone) ModuleDescriptor();
+    return new (zone) ModuleDescriptor(zone);
   }
 
   // ---------------------------------------------------------------------------
@@ -31,6 +31,10 @@ class ModuleDescriptor : public ZoneObject {
   void AddLocalExport(const AstRawString* export_name,
                       const AstRawString* local_name, Zone* zone, bool* ok);
 
+  // Add module_specifier to the list of requested modules,
+  // if not already present.
+  void AddModuleRequest(const AstRawString* module_specifier, Zone* zone);
+
   // Do not allow any further refinements, directly or through unification.
   void Freeze() { frozen_ = true; }
 
@@ -61,6 +65,10 @@ class ModuleDescriptor : public ZoneObject {
   const AstRawString* LookupLocalExport(const AstRawString* export_name,
                                         Zone* zone);
 
+  const ZoneList<const AstRawString*>& requested_modules() const {
+    return requested_modules_;
+  }
+
   // ---------------------------------------------------------------------------
   // Iterators.
 
@@ -95,11 +103,16 @@ class ModuleDescriptor : public ZoneObject {
   // ---------------------------------------------------------------------------
   // Implementation.
  private:
+  explicit ModuleDescriptor(Zone* zone)
+      : frozen_(false),
+        exports_(NULL),
+        requested_modules_(1, zone),
+        index_(-1) {}
+
   bool frozen_;
   ZoneHashMap* exports_;   // Module exports and their types (allocated lazily)
+  ZoneList<const AstRawString*> requested_modules_;
   int index_;
-
-  ModuleDescriptor() : frozen_(false), exports_(NULL), index_(-1) {}
 };
 
 } }  // namespace v8::internal