Eliminate imported_into pointers in Library

runtime/vm/object.h

Index: runtime/vm/object.h
===================================================================
--- runtime/vm/object.h	(revision 10983)
+++ runtime/vm/object.h	(working copy)
@@ -2063,11 +2063,8 @@
     raw_ptr()->debuggable_ = value;
   }
 
-  RawString* DuplicateDefineErrorString(const String& entry_name,
-                                        const Library& conflicting_lib) const;
   static RawLibrary* LookupLibrary(const String& url);
   static RawLibrary* GetLibrary(intptr_t index);
-  static RawString* CheckForDuplicateDefinition();
   static bool IsKeyUsed(intptr_t key);
 
   static void InitCoreLibrary(Isolate* isolate);
@@ -2088,33 +2085,20 @@
  private:
   static const int kInitialImportsCapacity = 4;
   static const int kImportsCapacityIncrement = 8;
-  static const int kInitialImportedIntoCapacity = 1;
-  static const int kImportedIntoCapacityIncrement = 2;
   static RawLibrary* New();
 
   void set_num_imports(intptr_t value) const {
     raw_ptr()->num_imports_ = value;
   }
-  intptr_t num_imported_into() const { return raw_ptr()->num_imported_into_; }
-  void set_num_imported_into(intptr_t value) const {
-    raw_ptr()->num_imported_into_ = value;
-  }
   RawArray* imports() const { return raw_ptr()->imports_; }
-  RawArray* imported_into() const { return raw_ptr()->imported_into_; }
   RawArray* loaded_scripts() const { return raw_ptr()->loaded_scripts_; }
   RawArray* dictionary() const { return raw_ptr()->dictionary_; }
   void InitClassDictionary() const;
   void InitImportList() const;
-  void InitImportedIntoList() const;
   void GrowDictionary(const Array& dict, intptr_t dict_size) const;
   static RawLibrary* NewLibraryHelper(const String& url,
                                       bool import_core_lib);
-  void AddImportedInto(const Library& library) const;
   RawObject* LookupEntry(const String& name, intptr_t *index) const;
-  RawObject* LookupObjectFiltered(const String& name,
-                                  const Library& filter_lib) const;
-  RawLibrary* LookupObjectInImporter(const String& name) const;
-  RawString* FindDuplicateDefinition() const;
 
   HEAP_OBJECT_IMPLEMENTATION(Library, Object);
   friend class Class;
@@ -2134,7 +2118,6 @@
   RawLibrary* GetLibrary(int index) const;
   void AddLibrary(const Library& library) const;
   RawClass* LookupLocalClass(const String& class_name) const;
-  RawString* CheckForDuplicateDefinition() const;
 
   static intptr_t InstanceSize() {
     return RoundedAllocationSize(sizeof(RawLibraryPrefix));