Support deferred library prefix syntax

runtime/vm/compiler.cc

 // 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.
 
 #include "vm/compiler.h"
 
 #include "vm/assembler.h"
 
 #include "vm/ast_printer.h"
 #include "vm/block_scheduler.h"
@@ skipping 557 matching lines @@
                i < flow_graph->guarded_fields()->length();
                i++) {
             const Field* field = (*flow_graph->guarded_fields())[i];
             field->RegisterDependentCode(code);
           }
         } else {
           function.set_unoptimized_code(code);
           function.SetCode(code);
           ASSERT(CodePatcher::CodeIsPatchable(code));
         }
+        if (parsed_function->HasDeferredPrefixes()) {
+          GrowableObjectArray* prefixes = parsed_function->DeferredPrefixes();
+          LibraryPrefix& prefix = LibraryPrefix::Handle();
+          for (intptr_t i = 0; i < prefixes->Length(); i++) {
+            prefix ^= prefixes->At(i);
+            prefix.RegisterDependentCode(code);
+          }
+        }
       }
       is_compiled = true;
       done = true;
     } else {
       // We bailed out.
 
       if (isolate->object_store()->sticky_error() ==
           Object::branch_offset_error().raw()) {
         // Compilation failed due to an out of range branch offset in the
         // assembler. We try again (done = false) with far branches enabled.
@@ skipping 359 matching lines @@
     const Object& result =
       Object::Handle(isolate->object_store()->sticky_error());
     isolate->object_store()->clear_sticky_error();
     return result.raw();
   }
   UNREACHABLE();
   return Object::null();
 }
 
 }  // namespace dart