Use unary class checks when emitting instance calls in optimized mode.

runtime/vm/flow_graph_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/globals.h"  // Needed here to get TARGET_ARCH_XXX.
 
 #include "vm/flow_graph_compiler.h"
 
 #include "vm/dart_entry.h"
 #include "vm/debugger.h"
@@ skipping 458 matching lines @@
 
 
 void FlowGraphCompiler::GenerateInstanceCall(
     intptr_t deopt_id,
     intptr_t token_pos,
     intptr_t argument_count,
     const Array& argument_names,
     LocationSummary* locs,
     const ICData& ic_data) {
   ASSERT(!ic_data.IsNull());
+  // Because optimized code should not waste time.
+  ASSERT(!is_optimizing() || ic_data.num_args_tested() == 1);
   const Array& arguments_descriptor =
       DartEntry::ArgumentsDescriptor(argument_count, argument_names);
   uword label_address = 0;
   switch (ic_data.num_args_tested()) {
     case 1:
       label_address = StubCode::OneArgCheckInlineCacheEntryPoint();
       break;
     case 2:
       label_address = StubCode::TwoArgsCheckInlineCacheEntryPoint();
       break;
@@ skipping 427 matching lines @@
       ASSERT(Utils::IsInt(31, disp));
       return FieldAddress(array, disp);
     }
     default:
       UNIMPLEMENTED();
       return FieldAddress(SPREG, 0);
   }
 }
 
 }  // namespace dart