Revert "VM: Simplify lowering of is-tests."

runtime/vm/intermediate_language_dbc.cc

 // Copyright (c) 2016, 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_DBC.
 #if defined(TARGET_ARCH_DBC)
 
 #include "vm/intermediate_language.h"
 
 #include "vm/cpu.h"
@@ skipping 183 matching lines @@
     test_cache = SubtypeTestCache::New();
   }
 
   if (compiler->is_optimizing()) {
     __ Push(locs()->in(0).reg());  // Value.
     __ Push(locs()->in(1).reg());  // Instantiator type arguments.
   }
 
   __ PushConstant(type());
   __ PushConstant(test_cache);
-  __ InstanceOf();
+  __ InstanceOf(negate_result() ? 1 : 0);
   compiler->AddCurrentDescriptor(RawPcDescriptors::kOther, deopt_id(),
                                  token_pos());
   compiler->RecordAfterCall(this, FlowGraphCompiler::kHasResult);
   if (compiler->is_optimizing()) {
     __ PopLocal(locs()->out(0).reg());
   }
 }
 
 
 DEFINE_MAKE_LOCATION_SUMMARY(AssertAssignable,
@@ skipping 1795 matching lines @@
   }
   __ IfULe(length, index);
   compiler->EmitDeopt(deopt_id(), ICData::kDeoptCheckArrayBound,
                       (generalized_ ? ICData::kGeneralized : 0) |
                           (licm_hoisted_ ? ICData::kHoisted : 0));
 }
 
 }  // namespace dart
 
 #endif  // defined TARGET_ARCH_DBC