VM: Use read-only handle Object::dynamic_type() where possible.

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 1485 matching lines @@
         String::Handle(Symbols::New(kEvalConst)),
         RawFunction::kRegularFunction,
         true,  // static function
         false,  // not const function
         false,  // not abstract
         false,  // not external
         false,  // not native
         Class::Handle(Type::Handle(Type::Function()).type_class()),
         fragment->token_pos()));
 
-    func.set_result_type(Type::Handle(Type::DynamicType()));
+    func.set_result_type(Object::dynamic_type());
     func.set_num_fixed_parameters(0);
     func.SetNumOptionalParameters(0, true);
     // Manually generated AST, do not recompile.
     func.SetIsOptimizable(false);
     func.set_is_debuggable(false);
 
     // We compile the function here, even though InvokeFunction() below
     // would compile func automatically. We are checking fewer invariants
     // here.
     ParsedFunction* parsed_function = new ParsedFunction(thread, func);
@@ skipping 371 matching lines @@
 }
 
 
 void BackgroundCompiler::EnsureInit(Thread* thread) {
   UNREACHABLE();
 }
 
 #endif  // DART_PRECOMPILED
 
 }  // namespace dart