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

runtime/vm/il_printer.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/il_printer.h"
 
 #include "vm/flow_graph_range_analysis.h"
 #include "vm/intermediate_language.h"
 #include "vm/os.h"
 #include "vm/parser.h"
@@ skipping 556 matching lines @@
 
 
 void StoreStaticFieldInstr::PrintOperandsTo(BufferFormatter* f) const {
   f->Print("%s, ", String::Handle(field().name()).ToCString());
   value()->PrintTo(f);
 }
 
 
 void InstanceOfInstr::PrintOperandsTo(BufferFormatter* f) const {
   value()->PrintTo(f);
-  f->Print(" IS %s", String::Handle(type().Name()).ToCString());
+  f->Print(" %s %s", negate_result() ? "ISNOT" : "IS",
+           String::Handle(type().Name()).ToCString());
   f->Print(" type-arg(");
   instantiator_type_arguments()->PrintTo(f);
   f->Print(")");
 }
 
 
 void RelationalOpInstr::PrintOperandsTo(BufferFormatter* f) const {
   f->Print("%s, ", Token::Str(kind()));
   left()->PrintTo(f);
   f->Print(", ");
@@ skipping 728 matching lines @@
 }
 
 
 bool FlowGraphPrinter::ShouldPrint(const Function& function) {
   return false;
 }
 
 #endif  // !PRODUCT
 
 }  // namespace dart