Store resolved library prefix in unresolved class object in order not to repeat

runtime/vm/raw_object.h

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #ifndef VM_RAW_OBJECT_H_
 #define VM_RAW_OBJECT_H_
 
 #include "platform/assert.h"
 #include "vm/globals.h"
 #include "vm/snapshot.h"
@@ skipping 333 matching lines @@
   friend class RawInstance;
   friend RawClass* AllocateFakeClass();
   friend class SnapshotReader;
 };
 
 
 class RawUnresolvedClass : public RawObject {
   RAW_HEAP_OBJECT_IMPLEMENTATION(UnresolvedClass);
 
   RawObject** from() {
-    return reinterpret_cast<RawObject**>(&ptr()->qualifier_);
+    return reinterpret_cast<RawObject**>(&ptr()->library_prefix_);
   }
-  RawString* qualifier_;  // Qualifier for the identifier.
+  RawLibraryPrefix* library_prefix_;  // Library prefix qualifier for the ident.
   RawString* ident_;  // Name of the unresolved identifier.
   RawClass* factory_signature_class_;  // Expected type parameters for factory.
   RawObject** to() {
     return reinterpret_cast<RawObject**>(&ptr()->factory_signature_class_);
   }
   intptr_t token_index_;
 };
 
 
 class RawAbstractType : public RawObject {
@@ skipping 671 matching lines @@
   intptr_t type_;  // Uninitialized, simple or complex.
   intptr_t flags_;  // Represents global/local, case insensitive, multiline.
 
   // Variable length data follows here.
   uint8_t data_[0];
 };
 
 }  // namespace dart
 
 #endif  // VM_RAW_OBJECT_H_